LoCAF25, Get the one that feels the best to you. If you like the Ruger P95-DC, you can always get a Ruger P94-DC. Its just like your P95-DC but in 40 S&W. Ruger makes an outstanding pistol, they may not cost as much as other pistols out there but there quality is great.
I don't have any experience with the Sig's or Springfield's XD-40.
I personally prefer Glock's myself, they fit me like a glove. I shoot them really well. There are about 18,000 police agencies in this country from the federal, state, county and local levels, around 65% of them use Glock's, there's a reason for that, if they work for them, I guess they'll work for me too!