I still haven't tried modo, but from what I've seen from the features demos it looks like it has a nice Unwrapping tool.

Have you tried the new Unfold UVs tools within Maya 7.0 as stavs82 suggested (it looks very similar to Blender's LSCM unwrapping if you've used it)

Zbrush won't really help your UV layout at all - at least not with Zbrush 2.0 - I haven't read up enough on the 2.5 features that will be available yet

I think the most monumental tool you can use for UV layout is an intelligent Relax tool - as in one that takes into account the size of the polygon on the geometry instead of just adjusting for equal spacing within the UV editor. This 'simple' tool takes a LOT of the work out of tweaking. This is in Max 8.0 and DeepUV I know - though I'm not sure what the restrictions are on the demos of these products. I'm not sure, it may also be available in other products.

Anyway, just my opinion