Well I'm an ASE Master Tech, I use mainly a large Craftsman set I got for my HS graduation 14yrs ago with great longevity out of it.. I have some Snap-on, Matco, and Cornwell... I have broke them all.. I like the Snap On stuff, but after having about 8 dealers come and go over the past 13yrs with LONG breaks in between, I don't want something that is impossible to replace.. They all have their perks and not so much perks.. Craftsman is easy because Sears is everywhere and they are cheapish..
My Fave is my 14.4v 3/8" cordless impact.. I am on my 2nd one now because I use the crap out of it.. handy, easy to regulate power, and good quality... I have had 2 different Snap On ones that SUCKED! My last 12v one lost the planetaries about 18mo after I got it.. Parts weren't available and there was no dealer around to be found to get it fixed.. Sucked to have to round file a $500 impact gun.. I still have the 7.6v one i bought 13yrs ago, but it needs batteries and probably a full rebuild.. haha