I was very happy with my MAC 1700 receiver and my AR2a speakers for many years, but after moving into a new house I replaced the speakers with a pair of AR3a's. As I suspected they were too much for my trusty old MAC to drive so I made the unfortunate mistake of replacing it with a Marantz 2270.
Don't get me wrong, the 2270 is a fine receiver and very well built, it just couldn't handle the load of the AR3a speaker system during bass heavy passages. It worked very well with 8 ohm speakers like the AR2ax and the AR5 but not with the 3a's in my living room. Everything on the Marantz was up to snuff and I even had a second one that I fully rebuilt but with the same results.
Sooo, I sold them both off and bought a huge super clean low hours Marantz 2330b. It had an exquisite FM tuner, very good phono section and plenty of flexibility in the preamp section but for the life of me I couldn't stand the way it sounded. Maybe it was the pairing with the 3a's but it sounded like a commercial PA system, very loud and "in your face" but kind of grainy and sterile at the same time. I really tried to like it (especially since it was a very expensive purchase) but I just couldn't do it. Again I went through it and everything was just as it should be, it just wasn't for me. Major disappointment.
I sold the 2330b and pretty much got my money back so not a big deal. I ended up going with a Pioneer SX-850 and the difference was like night and day, an excellent match for the 3a's. A few years latter I upped it to an SX-950 (only because a very good deal came up on one) and that's the end of the story. Not looking for anything else, happy as can be and have been for years. I did fully rebuild the SX-850 and the SX-950 (pretty much out of boredom) but it didn't change anything. I really like the Standard Radio built Marantz stuff but those two just didn't work out in this particular case.