I've successfully been trading in to Newport Coast for the past 12 years or so.
I own some Marriott Palm Desert L/O units which I reserve for Thanksgiving (TDI = 125), split and deposit in ii. I have been very successful in getting in to Newport coast with the 1 BR, and a few times was successful getting an exchange with the efficiency. My favorite time of year to go there is in mid Sept. The Newport TDI is around 115. So, sometimes the efficiency just doesn't have enough "pulling power". But in a lower TDI period (roughly Oct through February) I can typically get a match with the efficiency. Also, Marriott does bulk deposits of the shoulder season so it is often easy to pick two weeks back-to-back.
@Lakeshore If you are reserving a high TDI week (weeks 22-30) in Willow Ridge, and do a split, imho, you stand a
good chance of being able to book two weeks during the shoulder season at NCV. But your success really depends on you using "best practices" - - reserve highest TDI, deposit immediately, and do daily manual searches. Putting in a request is also a good idea, but you would need to have ii note that you need two b2b weeks. BTW, I just checked ii and see that there are two b2b NCV weeks (Feb 12 and 19th) available (I used a Palm Desert efficiency to search). The current inventory on ii are remnants of a previous bulk deposit or last minute cancellations. When Marriott does the bulk deposits and they are "fresh", there is usually more inventory to choose from.