Yeah, some films have clumpy grain. I don't know that it's just a T-grain vs. traditional grain thing either. Some films just have clumpy grain.
I think this is a reason that it's important to test out films you might not like in one format when you try out a new format. I'm not a fan of TMY, for instance, but I've seen some really nice work from TMY in larger formats. I know there are some people working in platinum/palladium from TMY negs, and I imagine that might be related to the fact that pt/pd has its own texture, due in part to the paper, and that can create its own effect in spite of TMY's clumpy grain.