Does anyone else feel like surefires quality has been going down hill? My first 6p is still going strong but the last two lights have had switched problems, eat batteries like they're Cheetos, and don't seem as bright. Looking at going to the new 511 light but I'm not sure yet. I really don't like straemlight, so are any of y'all using any other brands and how are they holding up on duty?

They quit making the Z2 and the 6P, and I think they may have quit making the C2.  
I really like those and the E series lights but used as hosts for drop-ins.  Lumens Factory D26 Warm fits my Z2 perfectly.  The Malkoff M61 and VME head on E2e is very compact and can use rechargeables.
 
For switch you may just want to get a McClickie upgrade if the new ones use the same size internals.  You can find them on Candlepower Forums.  Good for 5A.

I have an old G2 the eats the batteries if it sits there. I would say it's not a new problem you may just have gotten luck or well unlucky I have had many of their new lights as was impressed over the old ones.

I stopped using Surefire back in 2005 after switches kept break on me, the problem was they wouldn't depress at all when pushed.  Left such a bad taste in my mouth I no longer endorse anything of theirs.  Not like I'm a celebrity though

Skip the 5.11 light, it's junk.  We bought them for the new cars for two years and have had nothing but problems.  Most of the problem seem to revolve around the charges being crap.  Regardless, a dead light is nothing but an expensive paper weight.  For what the 5.11 lights cost they should be perfect but they are far from it.  I've got a Surefire G2 LED and am happy with it.  Also use Streamlight products and am equally happy with them.  I'd go with either over the 5.11 light.  I've got a metric crap ton of 5.11 products and this is the first I've wouldn't recommend.

Elzetta. Yes they're expensive but a heck of a lot better than Surefire and I thought my 6P was a great light. I have a G2 LED, 6P LED, and 3 cell Elzetta. The Elzetta feels much beefier/more stout yet slimmer in my hand.

Can't say that I have had any problem with any of my surefire lights. I still have a 6Z that is close to 20 years. Changed the head to LED and continues to work. Have 3 or 4 of the 6P and both my ar's run surefire and have been problem free. No switches have gone bad on the old ones and the lights purchased within the past few years have also run flawless. My problem is they keep improving the output so some of my older lights that still run great get handed down to the kids or extra lights for the glovebox. And because I have had such good luck with the surefire lights I myself would not look elsewhere for flashlights or weaponlights. Sorry you have not had the luck that I have had with the surefire lights.