I'm thinking of returning to the Meridian fold after an absence of nearly 30 years. I used to own a pair of M1s in the early 80s but family and other silly things got in the way.

I've been using Naim based systems with PMC speakers for many years, but I'm now after a change. So I'm thinking of secondhand DSPs to go with a Squeezebox Touch as a streaming only system.

What's the considered opinion on the differences between the 5000 and 5500 as it seems the 5500s are generally about twice the price of the 5000s on the s/h market.

Is this worth it, or are diminishing returns at work here?
I'm not after the nth degree of sound, just a good bang for buck. Otherwise I'd look at 7000/8000s but I'm still married so they're out of the question.

Thanks for any pointers.