Hi , Your amp and its brother the MC-250 (which looks the same as the earlier tube amps like the MC-240 & 275) were the first solid state amps McIntosh built. The 2505 is, I beleive, the first Mac amp with the blue meters and is quite collectible for both those reasons. To compare it properly you have to listen to solid state amps of the day (it was introduced in 1967). Your Rotel is a fairly decent modern amp but I suspect your reaction may be colored by the quality of the signal you are feeding it. Neither amp will sound fabulous with a mediocre signal. If you are starting to upgrade your system you should start at the front end. I am running a pair of bridged MC-250's with an Arcam FMJ CD-23 and a McIntosh C-40 pre. They sound very good although they probably don't have the last word in resolution etc. The other neat thing about your amp is that you can take the line level output from CD player directly to the amp and control it with the gain controls. This way the amp is getting a much purer signal.
Bill
Bill