I was sort of the group leader of the small group of 26 (not sure how I got roped into THAT), mostly DNY members of ScubaBoard who stayed at the Plaza this last June/July, some of whom chimed in above. I have been returning to Bonaire at least once a year for the last 6 or 7 years, and this was my gf and my second time staying at the Plaza.
We were also there last summer with another group of ScubaBoard members, many of who put on this year ScubaBoard Invades Cozumel. We all had a great time, but as always, not every little thing goes perfectly, not everything as smoothly as you hope, and it helps to be able to adapt and overcome small things.
Bonaire is Dutch, so small hand towels are not normal ( it's a European thing I hear). It is the Caribbean, so service can be slow, even irritatingly slow at times, anywhere you go on the island. It is an island, so not everything is in stock in the stores at all times, and purchasing small items and food can be costly. Most of the resorts, Plaza included are not new, and none are 5 star. THAT is simply not what Bonaire is all about.
As there are few flights in and out of Bonaire, so the plane you arrive on may be the very same plane taking the previous occupants of your room home, so rooms often take a while to get cleaned again, and ready for the next group of occupants (you, me, etc). That Can be irritating, after a long red eye, but to me it is not a hill worth dying on if I have to wait. I always find a way to go dive while I wait for a room, if I have to. That sure has a way of adjusting my attitude!!!
The rooms are more than adequate. As said the breakfasts are quite satisfying, and do provide a decent way to make yourself a lunch sandwich too!
The dive op is friendly, and they bend over backward to try to make your stay a good one.
As a perspective: we have stayed at Buddy Dive several times, Den Lamen once, and off resort more than that. I would gladly use any one of these places, including the Plaza again tomorrow. (Dam sure wish it WAS tomorrow)
In short, if you chose the Plaza, you will probably have some minor issues, but then that may also happen anywhere else too, but you should find that everything is good, sound, well priced and more than sufficient, as long as 5 star, butler is NOT your expectation.. You should definitely have a great experience, and enjoy truly awesome diving.