Having Diecast or not doesn't really bother me, but a few observations:

If done on the right toy that's well designed it can be excellent (I'm thinking MP-01, or 04 which is the one I have). The thing has a nice weight to it and it stands up without any issues (Mine has never toppled over, and everything is still tight to this day).

I think the diecast giving the quite substantial figure some weight is really nice (I'm a fan of watches as well, and a lot of people prefer stainless steel over other materials, like titanium, in part because of the weight it gives the watch. Not that I can afford an expensive watch myself..)

My Alternity Prime on the other hand I greatly dislike the diecast. He's way too top heavy, and if I recall correctly, the thing that's holding him up is a plastic heel (that may have been something I did upon recommendations from others, because he kept toppling over).

Having said that though, I wouldn't pay a premium for Diecast (I'm lucky I got my MP-04 prime for about as much as I'm going to pay for the re-issue of MP-10), which is probably why I got alternators instead of binaltech.