I had an infidel ultra. Thankfully it was part of a trade package and I didn't waste any of my own money on it. IMHO it completely sucked compared to cheap eBay hybrid leather/kydex holsters.
It felt like it added to much bulk. The leather was too thick, and the single belt clip made it feel unstable, the holster wanted to shift around.
Right now I am using a Tango Concealment holster, which was purchased off ebay. Crossbreed style, leather back, kydex shell and two adjustable metal clips. Extremely comfortable for use carrying all day (8-9 hours in Phoenix, AZ heat).