Here's another vote for the
Bianchi Model 135, it is my primary carry holster and I have one for my Shield and one for my 40c. (link is a front and back pic of holster with my 40c) I have been using them for going on 2 years and I must say it is a VERY COMFORTABLE holster, even more so than the MTAC I used prior to it breaking. It has a mesh covered foam backing that is extremely comfortable against your skin even on those 100 degree days.
One thing I think is very important when it comes to IWB holsters, especially if you plan on tucking it are the belt clips. Unlike some holsters that come with huge metal or kydex belt clips, and/or have garish emblems on them the 135 comes with C-clips which almost disappear on a black belt. The C-clips are made of a super strong polymer material that doesn't scratch your chair and is easy on clothing.
You can find them on Ebay and Amazon for under $50.
Good luck!