I have been increasingly disappointed with Bonvoy over the past 18-24 months, with minimal to non-existent upgrades and packed lounges with mediocre offerings. IMO, there are just too many elites. I know some people get excellent upgrades by reaching out to management ahead of the stay or making a ruckus at check-in, but I hate playing those games, so often end up with high floor or similar non-upgrades. I used to be a huge fan of Marriott's BRG, with hundreds of successful claims over the years. It is still the most honest BRG out there, but has become much tougher. And some points requirements are just insane, Sheraton HK or Marriott Hamburg at 64k/night. Similarly, there's not a lot of excitement on the earn side. That said, I'm LTT, so the decision to have fewer Bonvoy stays is an easy one. I will stay at Bonvoy hotels I like or if I can get a reasonable BRG or the points rate is fair. But Marriott has become my third program.

My first program, IHG Diamond with Lounge Pass has been a delight in the last year and a half. First of all, there have been some spectacular points deals (see, for instance, my posts here, here or here) over the past years. Lounges at ICs and Regent are generally far ahead of those at Bonvoy properties (often serving champange and high quality foods), most hotels make an effort to upgrade (often to junior suites or better, far eclipsing what I get at Bonvoy hotels), and breakfast benefits are generous. Of course, IHG Platinum is worth nothing, but Diamond is great, and the Lounge Pass makes it even better.

Finally, I'm Hyatt Globalist, which is great in terms of upgrades, lounges are generally better than Bonvoy (although behind IC and Regent), and breakfast isn't an issue. Hyatt has some resonable redemptions, but revenue rates are generally higher than Bonvoy and IHG. And the Hyatt BRG is a scam.

The biggest problem with Hyatt is the limited footprint, with dozens of desirable locations in Europe and Asia having no or poor coverage. This also applies to IHG to some extent -- while Regent and many ICs and Kimptons are very good, and there are a number of good Indigos, Voco, and CP, in many locations you may find that IHG only has older CP/HI or HIX/whatever (which don't really do the trick for me), while Bonvoy has better hotels.

I realize this isn't a super helpful answer for you, because I can simply fall back onto LTT with Bonvoy so don't have to make an effort to requalify, and I also have more nights annually than you do, so it's easy for me to cover three programs. That said, IF the IHG footprint works for you and you can make it to Lounge Pass (40 nights) and Diamond (70 nights, but occasional promos that make it a little easier), that'd be my recommendation. Note that for Diamond or LP holders, the following are incorrect (emphasis mine). For Diamonds, breakfast is available at all brands, and regardless of status, award nights count for status qualification.