[Tricon]

I like just about every map size. Though for SP games I prefer large-huge maps. I haven't played a big map in MP yet, but considering that this game is made for PBEM I see no real problem with it.
For an afternoon hot seat game I like the "Aran" size maps. For a weekend game the "Orania" size.

For me, bottlenecks are as much a storytelling device as a strategic position. So I like'em a lot, but too many of them kind of defeat their purpose. Unlike others I do not like the "clear one valey at a time" expansion of HoMM. Holding a bottleneck should give you an advantage, but it has to be possible to circumvent them.