Vintage Onkyo gear vs Adcom


Looking for some help on the budget upgrade path:

I currently have an Adcom GFP-565 and have been searching for a power amp to do it justice.

In the course of my research I have stumbled upon quite a few Onkyo integrateds from the late 80's--early 90's (a-8800, a-890 to name a couple) that look very appealing.  I have heard the Adcom and also some Onkyo stuff from that era and they seem much closer in performance than I would have guessed.

So my question is this: should I continue to pursue a power amp for the 565 or sell it to purchase one of the high end Onkyo/Integra integrated?

Thanks

84miles
It’s interesting that there is such a wide array of opinions on the Adcom gear.  I’m currently driving B&W 684’s—so not sure if the 535 is up to task.  I’m sure the 555 is great but that’s a big price jump from the 535 or 545.

Then there is always the option to dump the Adcom pre and go for the Rotel/B&W synergy...
I believe I woulf sell the preamp and purchase a used  integrated of more recent vintage? 
the b&w 684 are rated at 87db, which makes them relatively hard to drive--the 60w 535 might (or might not) be enough amp (b&w recommends 25-150w, which isn't terribly helpful). i've found adcom to be conservative in its power ratings, but if you're concerned you can try the higher adcom, rotel or something like parasound hca, which is excellent value.
Mesch,
Thinking I would want to max out at $800-1000 if I ditched the Adcom.

Dr Loomis,
I've also heard good things about the Parasound and Rotel gear. Perhaps snatching an Adcom could be the short term solution while saving for the right integrated.  Do you remember what you didn't like about the 545?  I've only ever heard the 565 mono blocks.