Midwest Gun Works did the triggers on on my 425's and I am quite happy with the job they did. I was hesitant to buy a Browning because of the poor trigger many have and was right. The triggers on my two Sporting 425's were pretty darn crappy when received. After Midwest did their work, they are close to feeling like much higher end guns. No creep and very little overtravel. Crisp break at @3.5 lbs. That was 10,000 rounds ago on one and 5000 or so on the other. All in all, I am happy with Midwest.
One thing I like about Midwest is, if they screw it up........they sure as heck have the parts on-site to replace it.
http://www.midwestgunworks.com/page/mgwi/ctgy/gunsmithing-pricelist
Also, I have heard only really good stuff about Arts Gunshop in MO. No personal experience with them however.