well, before i bought my vit, i looked at about 10 or 15 sierras, within a price range. i had my mind set in getting a sierra, and thats what i was looking for. but hardly any of them appealed to me.
then, the very first vitara i looked at, i bought. it just felt right, even though the vits condition was worse than some of the sierras i looked at.
anyway, go with what feels right. look at it, drive it, look at it, and go with the flow.
with tech now, the sierra is the way to go if you want a real bad a$$ trail rig, as mods are easy to do. SPOA, RUF, SR, Yota Diffs etc etc etc. easy peasy. theres a lot of support for the sierra. ride quality is what you make it, and cab size is little to be desired.
with a vit, parts are less readily available, more fabrication work for custom parts and installs etc etc. spacious interior lets you stretch out, and not feel so confined. ride quality starts off good from factory, and as things are, can always get better from there on.
i havent regretted a single minute i've had with my vit.
good luck, and heres a couple of pics.