Well, Ugadalou i think did a good resume. as well other posts i agree about Tsonga power that should be more significative @ FH.
More generally, i think a better balance should be found among the whole roster, about the power & spin stats, and the way they interact.
One important thing that should be preserved for each char in the roster should be the ability to score a winner. For some char it's a breeze and for some others it's too difficult or almost impossible due to high top spin.
I think maybe the top spin range should be reduced, maybe using a max value like 80% for nadal, and lowering other heavy lifters values accordingly.
In managmes tour lots of players play with like 90% power and 0% top spin (...) always seeking for the fastest shots (we are not getting there but i just want to mention, that faster shots in TE is a better weapon than spin, as long as the players are experienced with the game, and they play with sim controls).
It's true that high top spin shot can cause some trouble but most experienced movers will send it back again and again and will finally kill you with a good flat stroke. (at least from my own experience but i still have only like 6 month of play i'm not a TE veteran).
As an example we played very, very long rallies with Eliomelma in Barcelonna (nadal vs nadal), the match lasted more than 1 hour. at some point we had no more stamina and where just moonballing top spin shots at center, and finally one of us just hitted the wind missing the ball, probably hypnotized and falling asleep

Nadal best weapon to finish the point shouldn't be to take the net.
Though it would be much different if we used Elite controls. This would shorten some rallies due to placement errors more often. But this control scheme would also probably put off the beginners. Therefore i suggest for the future to keep sim controls for small tourneys like challengers, atp250,and use Elite controls for larger tournaments. Or maybe another choice could be Using the Elite controls after the 2 or three first rounds of any tournament (in the final rounds).
About the power and spin balance, i think the guys which should be looked at are, Nadal, Ferrer, Almagro, Verdasco, Gasquet (especially this BH is disappointing, he should be able to score more clean winners with it) , Roddick ( i feel that he hits faster and flatter shots than this).
Maybe djoko and murray should have a bit less spin, really not sure though.
In a general manner if you want more spin dont hesitate i think to increase power because it's just not translating really in more power than other chars, what has to be found is a realistic ball speed as much as possible. Not comparing raw power stats because it's too much influenced by the spin. what is important is the shots efficiency balance general feel in the end, also depending partly the shot anims.
Tier 1 char in my opinion are actually : Federer , Simon, Djokovic, Davydenko. Maybe murray .. i didnt played much with it i can't say, Nadal : in present setup i don't think so, or a very boring Tier1 not worth to play but to mesmerize your opponent to death, but it's too sad not too be changed
I feel that Federer is over the pack and is an advantage to play with, a big
one if you play vs a Tier2. A not so big advantage agains other Tier1 but still. Federer is really an amazing shotmaker in this roster, especially with the forehand, i think Ugadoulu has a good idea gimping him a bit on backhand consistency.
About Simon though i think if you know how to play a counter properly he's probably the strongest char with such stats, but you should ask some TE veteran to confirm this.
I think the only counter in this roster is pretty strong and should be tuned down, honestly, Simon top spin shots are almost faster balls than some roster char accelerations. also he's really fast and has a very good stamina compared to some other chars. It'smaybe too much for a counter in this roster, he should maybe be balanced with a lower speed like between 70-80% (from kyujji own words when we chatted 60-65% should be enough for a counter, though i feel it's still too slow for Simon wich is pretty fast in reality).
Also he can hit very fast balls even as a counter with standard shots with this 10% spin stat, even with 75% power. And finally he use less stamina than other chars styles, and still has a very good amount of it as a base stat (87).
Djokovic is pretty balanced, maybe giving him a bit less top spin can be a good idea, but then reducing his speed a bit to balance him, it's about how you feel it.
The Heavyweight class : Del Potro, Soderling, Berdych
Well i don't see much interest using Soderling when you can use Del Potro. Same speed, better stamina for Soder, but Del Potro shots for approx same power are way faster due to very low spin (12% vs 35%), and also has better FH/BH consistency, still a good serve (almost equal), so i think he's a better char. Abit disappointing cause i would like to play Soderling but for now he doesnt has much appealin comparison. Maybe increasing his speed to 75% should do the trick, would it be reasonable ?
Just as a small comparison, i feel that Federer is a harder hitter than Soderling in this roster, when playing a matchup, same FH power, but less spin for Federer, and better backhand for federer. Add that 20% slower Soderling.. at same level of play you get easily trashed. Only Del Potro or Berdych power can eventually make for it (but i still dont think so because 20+% speed difference is too much).
Berdych is pretty good alike Del Potro, but 60% speed starts to be too low for me, if he doesnt take control of the point right away, just move him left & right then kill him
At least Berdych has some trade-off with all this power and low spin for fast bombs.
Isner or Tomic are slow and doesnt have much trade off, Isner is weaker than lot of chars in the roster in the power, consistency area, just has a serve but is slow, Tomic has good all around abilities, but the combination of slowness and very poor stamina make him useless in my opinion.
I would rather go for 2 tiers , not three, for this reason,i don"t see why use them, maybe for fun trying to pass thru one or two rounds in a tournament with, since there is still much beginners playing the game, butas soon as people will be a bit more experienced, i think they will become totally worthless. So my opinion is , just drop them, or balance them.
llodra / lopez : well i think i won't ever pick up a char with such a lower consitency (<50%) on any wing (bh or fh), it's too much penalizing in my opinion in TE, as much as the stamina goes a bit down, this leads quickly to ue's. I think one should not go so low on this stat, but thats just me. Still Llodra is very fun to play at the net.