Generally the wider the sole width the more turf forgiving the iron can be. Also, generally, more bounce can be a game improvement feature, depending on the players angle of attack and the turf conditions they tend to play on the most. One thing that many do not realize is that the more sole width you have the less measured bounce angle you need. Wider soles play like they have more bounce. We have always tried to balance the two, sole widths and bounce, to offer the best combination for whatever design we have created. We also progress the bounce throughout the set on almost all the sets we develop, with a little less in the longer irons to a little more in the shorter irons. We also vary the sole widths, depending on the model. Currently we have sole widths ranging from .755″ on our TS1 Forged blade to .850″ on our STi2 progressive cavity irons and .931″ on our just released M890 irons. We have, in the past created sole widths much wider in models that were designed to be Super or Ultra Game Improvement Designs targeted at higher handicap players. Out MP-1 set from a few years ago had a sole width of 1.318″. We still have a few sets of those remaining. I don’t want it to sound like you have to have wide sole widths to be super or ultra game improvement clubs. You don’t. Wide soles do provide some players more turf forgiveness, especially if they have steep attack angles and/or play in softer turf conditions. More bounce can do the same, but you have to be careful not to get too much bounce in your full swing clubs, especially if you play on firmer surfaces most of the time.
If you have gone from hitting shots fat to now hitting them thin, then obviously something has changed in your swing. You might consider having a qualified teaching professional take a look before you decide to choose a particular type of iron. If you have gone from hitting shots fat to hitting them thin, it is quite possible your attack angle has changed.