I had a 275 for a few years and now own a pair of m120. For the application I use them for I prefer the m120. They are two different amps, with the 275 having more of a traditional tube sound. Also, the Rogues can be used with a wider variety of speakers and present with more weight on the bottom and see to be more pronounced up top. Again, a lot will depend on the speakers you match them with. Coupled properly you would not be disappointed with either.
Mcintosh mc275 or rogue m150/180
I love my current Dennis Had aes six pacs. I just retubed them today with Mullard reissue el34s. But I didn't buy a set of andra speakers I had my eye on because I was worried the amps weren't quite enough juice. As I ponder future improvements I am curious as to thoughts on improving sound and output. My six pacs are my first foray into tube monoblocks and I am hooked. I honestly can't see how they could sound better, but I have made that statement before and been proven wrong.
Brad
Brad