One of my local LGS's is a Sig dealer. As such, they have a nice selection and I was able to compare/contrast those 3 specifically.
All in 9mm.
1) p226 Combat TB - $850 used / on consignment. 3 dot night sights
2) mk25 - $1050ish(memory fail) new 3 dot night sights
3) TACOPS - $1185ish - TB SRT beavertail fiber optic sights.
I had noticed the combat on a previous visit and wanted to compare the SRT with the standard trigger.
It IS a shorter reset, but barely perceptible to me. Non-issue in my decision process.
Beavertail was also a non-issue for comfort. Bore axis is high enough that slide bite is probably never an issue.
Sights, the fiber had nice pop, but the trijicon 3dots are nice too.
The 20 rnd mags that come with the TACOPS work fine in the other 2 guns as well. The TACOPS has the magwell, but I don't really care for them.
Functionally, the all have the same controls. The trigger pull is same, sans the shorter reset. All very nice.
Bascially, the factors in the buying decision come down to price and esthetics, what looks nicer to you.
The Combat TB came home with me that day, and bought 2 extra 20-rnd mags.
Shot it yesterday, and made 1 nice ragged hole at 7yrds. A real joy to shoot!
Hope that helps.
V.