i dont know a lot about the nikon offerings... but the range of the lens you speak of is massive!
18-200... there may be some "tunneling" near 18mm, and soft; and soft towared 200mm... but that is something you'll find out specifically when shooting... what settings make for good shots etc.
one key thing is that the lens would virtually never need to be changed! that has its own benefits
it sounds like it isn't a bad quality lens at all... and you will absolutely LOVE VR... i have only tested it so far... but good god, its magic
my own opinion.... go for it
