Sometimes I use DMG group checks, sometimes I use 'weakest/strongest link', sometimes I don't lump the checks together. It's all very situational.
For examples: even with just stealth, I'd do a DMG group check for a long sneak where the stealthiest can scout a bit ahead, find the best path and guide others, etc. If they're too close to the enemy to communicate stealthily, they each roll and if anyone's spotted the enemy is alerted. (although they don't necessarily see everyone) But sometimes they're far enough apart form each other that each pc's success or failure stands independently, and I need to know who's seen and who's still hidden.
(Strongest link would be like a perception check when the party can communicate: if anyone sees it, we assume they point it out to the others.)
I do prefer to use DMG group checks when possible; it's the teamwork-iest version, gives the specialists a chance to shine a bit, and keeps one bad roll from ruining everything.