1) I use Dragonshields primarily now. My current deck, LycanZoroark, is sleeved up in a black matte set of 'em.
2) I've tried a few sleeves. Old and New formula KMC Hypers, Ultra Pro Regulars, Mattes, and Eclipses, the sleeves that come from the ETBs, and, of course, Dragonshields.
3) My Old formula KMCs were amazing. They're pretty trashed now, which sucks because they were great sleeves. Don't even try with the New formulas. It's impossible to distinguish the two from card shops, so I just say skip over them entirely. If you want something similar, go with Ultra Pro Eclipses. They work well, they have a nice shuffle feel for a while. Once you've used them for a while, though, they become really stiff and dirty. Once I put in the money for Dragonshields I never looked back. Great card sleeves, durable, can make it through rigorous playtesting, game after game, and will still be near intact. You are downgrading on shuffle quality, but it's not by too much; they still feel amazing. Don't even try with ETB sleeves, they're those foil art sleeves that peel after a day of play. Not something i'd assume you'd be looking for.
4) I just bring whatever I have left of the color Dragonshield I was using. I usually only buy 100-packs, except for the Crimson ones (which are my favorites), which, I bought a 60-pack
Overall, I love almost everything about Dragonshields. They're fantastic sleeves, and I highly reccomend.