AbdulAlhazred
Legend
after the fiasco with the pathfinder synthesist/paladin multiclass a few years back, multiclassing is banned. Forever. Anyone who brings it up at my table will be exiled and shamed and then mailed to australia. I managed to find a workaround for the missing pages/corrupted files that may not be against ENworlds rules so I won't share, but the final houserule is anything from the essentials line is banned unless I approve it. Simply because essentials is a goddamn trainwreck waiting to happen. Ranger/warden/artificer is the current party lineup.
4e MCing is a whole entirely different beast. It is usually considered a bit weak, but actually if you know what sort of stuff you want, then it can be VERY much worth the cost of a feat to get access to a specific highly valued power! And of course the 'base' MC feats are almost all well worth taking simply on their own, so overall its a pretty good deal and there's no brokenness or whatnot involved.
The hybrids presented in PHB3 actually also work pretty well. I think they add more complexity than they are really worth, in general, and only a small subset of all the permutations are really worthwhile, but they certainly don't hurt the game overall. Nor are they 'broken' in any real sense. A few classes, swordmage most famously, seem to add a rather large amount of value as hybrids, but the results aren't crazy or beyond what you could achieve with single classed characters. Its just another path for optimization. Personally I let players use them if they want, but I don't really encourage it actively.
Most of my players figured that MCing was a pretty good deal, but only a couple of them every went beyond the base MC feat. 4e classes are so flexible already, particularly with themes and whatnot in play, that it doesn't seem like the big deal it was in 3.x or AD&D.