I have a 2235 and a 2270, both in wood cases. The 2270 is in its original case and was owned by one guy before me. Upon his death, it was sold off by his granddaughter. The power button is a bit funky. I'll replace it when I rebuild the amp and preamp boards and service the dial (light bulbs and velum paper).
I picked up the 2235 on ebay but it arrived in good condition. I paired it with a gorgeous wooden box I purchased from Vintage HiFi Audio. The owner, Aaron, is a true craftsman who does beautiful work. It's nicer than the original Marantz boxes. The African Paduak finish is to die for. My 2235 has a bit of a hum from the amp itself. I'll rebuild the amp and preamp boards on this one too. I'll also service the dial on this one.
To my ear, the 2235 has a slightly better sound. A bit more detailed and refined. But the 2270 has a real warmth that seems similar to the sound of the tube amps that came before. Not a huge difference between them. Both are incredible. I've heard other Marantz receivers but never had them next to one of mine or hooked up to the same input or speakers, so it's hard to compare sound. Not a ton of difference though. I think all the 70s models sound greats.
I also have a 2005 Marantz which I don't like nearly as much. I also have a 2007 Dennon which sounds real good. Not as warm as the vintage Marantz models but very rich, smooth and dynamic with its 110 watts per channel at 8 ohms. This surprised me, as I expected the vintage stuff to sound way better. Got it for one tenth as much as the vintage Marantz units.