I have carried my spurless Sp101 in .357 for about 8 years now. I do carry it front pocket on occasion (in a holster), and it works fine. I would not recommend any tumbling or anything. It does make it much quicker to present if you already have a hand near your pocket, or even in the pocket. I also have an inside the waist band holster. It gets a lot of ankle carry as well (not as quick to retrieve, but with long pants on it is convenient).
I have done a few extremely minor things to it. I deburred the hammer face, and broke the corners a bit. One problem with it is if you get fabric (ie shirt material) in between the hammer when it goes click, it can be very hard to get out. You can't pull the trigger again, because it has not returned to battery, and the shirt can be hard to get out because the sharp edges on the inside of the hammer. I also broke a few more edges that were cut a bit sharp.
It is a very very strong revolver. It is a pleasure to shoot even with hot heavy loads, due to the weight. Shooting full power loads through super lights is not pleasant. But they are much more convenient to carry.
I can empty the .357 with full power loads very fast one handed with no worry of it being uncontrollable, even with 158 grain loads.
It is probably the best value in a gun around.
Of course I love Ruger 10-22s, Blackhawks, and especially MarkI, II, III's etc.
The grip on the sp101 is also different from most revolvers. It is a "stick" type tang or grip. You can put all kinds of different custom grips, and you are not limited to the size of the grip frame like on many guns.
Customizers also can do really cool stuff with them. They are super stout.
http://www.geminicustoms.com/RugerServices.htm
Wow, sorry those were not that size when I linked them.
Even Bowen offers custom work on them (specalizes in custom hand cannon conversions of Rugers etc)
(bottom of page).