I'll be at the Marriott there in late June also. Happy to hear Hilton may finally have something in Maui, but I'm having a hard time imagining that location being comparable to my 2-bedroom oceanfront at the Marriott. Plus, you can buy a 2-bedroom OF at the Marriott for about $32k on the secondary market. If a Hilton is ~100k, again... hard to see how that works out.
I don't expect the resort to have views comparable to your Marriott OF (or Westin WKORV OF) because it is across the road instead of directly on the beach. But it will be good OVs. I imagine that the developer retail prices will be in the same comparable ballpark.
However, if you trade your existing HGVC points (plus buy another inexpensive resale with low MF/pt to meet the high pt requirements) to trade in during club season, I expect that will be a MUCH better deal than paying $32k for a resale MOC OF.
We were considering buying another week to add to our WKORVN, but I now view MBV as a more economical way to stretch our WKORVN week on Maui to a longer stay. Sure, we need to move resorts and there is the difference of OV vs. OF. However this raises the question as to whether this is "good enough" for saving $22k+ ($32k MOC minus $10k HGVC resale) on another MOC or WKORV resale purchase - it becomes a personal preference of view, location, and discretionary budget as to whether an extra $22k+ is worth it.
We still get our OF beachfront week at WKORVN, then can get another week at MBV, a comparable quality resort, (but not OF). We are not burdened with a high Maui MOC or WKORV MF of $2500 - $3200 per week and could save more than half of that annually with the right HGVC resale unit.
Of course, this strategy assumes decent club window and unit availability. It probably won't work during event weeks and July/Aug. However, the high point values will keep many people opting for BI or Oahu and reduce demand.
If this HGVC strategy doesn't work, we can always pick up a resale WKORV or MOC OF which, to your point, is much more cost effective than retail.