i've only been to the tribecca grand and only for a party at the bar. but both hotels are pretty upscale boutique hotels. i just have to say that most nyc hotels are kinda a disappointment because unless you're staying at a suite, the rooms are pretty tiny in comparison to other hotel rooms across the country.
the soho grand is on west broadway just a little north of canal. you're basically at the perfect starting point to do serious shopping in soho and nolita. i also think staying downtown in a place like the soho grand is cooler than staying at a tourist-y place in times square. there is definitely more going on restaurant and nightlife-wise in this area than uptown... even though at a mid-town hotel, you may walk out and boom you're in the center of the theatre district... at the soho grand.. you may have to walk a few blocks to get where you want to go.. but it's definitely a cooler part of town. IMO.
on a con note, it's close to the holland tunnel entrance i think.
i just want to say that i did my first SERIOUS shopping trip in soho today (i've been several times before, but with a boy, so it kinda sucked for shopping) and let me tell you that that area RULES. There are SO many shops, chains and boutiques- i went or walked by: bloomingdales, anthropologie, h & m, club monaco, chanel, burberry, riess, gap, ann taylor, etc.- lots of chain stores, miu miu, prada, diesel, miss sixty, A.P.C., Daffy's, nicole miller, laundry by shelli segal, barneys co-op, intermix, scoop, Temperley, some really cool boutiques (flying a had stuff i liked the most, pricey- their vintage was super overpriced), gosh, i know i'm forgetting so much.. I would so much rather stay down there than midtown (which is easily accessible too). Don't know about that hotel, but I think it would be really fun to stay in soho. Also, if you don't mind walking a lot on a nice-ish day, there are other really really cool areas in a one/two mile radius- lower east side, nolita, meatpacking district, chinatown (soho is really close to this area), chelsea, the village (of course, theres always the subway or cabs too!) You'd have to walk a lot of blocks to get to some of these areas (maybe 20-30?) but its my favorite way to explore a city and soho is central to all these areas.
I wish I was going. I've always wanted to, and now I know which area to stay in WHEN I do. But, I was asking for a friend. Thanks for all the info. She'll really appreciate it. She's a world class shopper!