Yeah, I can't think of a reason a MVC owner would deposit to SFX, which explains why they have no Marriott inventory. I could see maybe if a MVC owner wanted HGVC on the big Island.
I'm very curious how the math pencils out for SFX vs II for a Grand Luxxe trade.
For my next Grand Luxxe trade through II I paid or will pay:
$209 exchange fee + $59 size upgrade + 640 Vidanta fee.
SFX has the $99 fee, but their exchange fees and upgrade fees are more, plus iirc they charge an "elite" upgrade fee to access Grand Luxxe. I'm not positive about those fees but I think it's around $249 exchange + $99 size upgrade + $299 luxury upgrade + $75 vidanta fee.
That's less but not dramatically so, and ii has gotten me a 2 bedroom GL over my spring break, and 4 bedrooms in the fall. Do you think SFX would be able to get a 2 bedroom over spring break?
Yes, the SFX math you list above is about right for a non-Diamond member. I would pay $149 exchange fee, free upgrade, and $299 upgrade +75. Although I'd have to factor in my 2,400 point Vegas Hilton exchange vs. my 2 BR II deposit, but everyone's mileage will vary on what they own and their MF/costs are.
My HGV is about $0.18/point for MF, so my "true" SFX GL cost would be:
2400 HGV point = $432 plus the $67 booking fee and $52 Guest cert? = $531
SFX Exchange fee of $149, plus $299 + $75 = $523
Total: $1,054
Now, if I did II:
$950 is my MF for my 2 BR week
$179 II membership fee (I think that's a 1 year membership? or was that two?)
$209 II booking fee
$640 Vidanta fee (since II is like for like, I'm depositing a 2 BR and getting a 2 BR)
Total: $1,978 (maybe a smidgen less if I got the II membership fee wrong)
I'm not counting SFX membership fee because I've already broken even/come out ahead with what I paid and what I've saved, so basically for the next 10 years my fee is "paid for". Although even if I didn't fact that in, it would've been $50/year
but again, YMMV and your HGV points may be a higher or lower MF (I think the lowest we've seen is like $0.12/point MF for Hilton). But some are higher are like $0.30 (ouch)
Go with what works well for you. Try to stay at the Nuevo Vallarta location because the Riviera Maya location totally discriminates against ALL exchangers into Grand Bliss/GL units (even a Vidanta owner using their SFX bonus week gets discriminated against). By discriminated against, I mean you will *not* have access to the Riviera Maya Grand Luxxe Pool, the Beach Club, or the Burger custom Made restaurant. Unless you want to endure the 4+ hour "sales presentation".