, sometimes the reason people do not replace stuff has nothing to do with possible improvements having been made. Sure nothing wrong with a 2300, heck another company liked it so much they basically copied it. That is definitely high praise , because we all know that saying about imitation. Sometimes you just like something, it ' easier to not replace something than it is to replace it. I have never owned the 2300. I did have an MC 2500 and the biggest reason its not here still is it developed a flaw, which no local repair shop around here could manage to fix.
I have read there are those who have heard and lived with all three 2300/2500/2600. some of them say the 2300 beats them all, maybe it does, I can't say, I have only had one of them, and a few "too late" attempts to get a 2600.
I think sometimes a piece of gear is just made in such a way, that some people just aren't interested in replacing it. After owning a 2500 and knowing full well how heavy and cumbersome it is to transport. I only weighed about 40lbs more than the 2500 did when I got it, lol.
I think the 2105, c 28, c33, MC 2205, c2300 MC2300, MC452, MC275, seem to be the most loved pieces produced by this company. read SO many posts about each of these pieces, and so many people who have them, use them forever. in those instances, they got just about every aspect of a piece of gear right,, from the sound down to the fit and finish.
Something I forgot, perhaps the MC 2300 is so beloved, is I do not think there was an amp that compared to it at the time of it's release ( perhaps it was the ONLY dog at the time.)
have I left out a model? it seems the MC 2300 is one of a handful of special amongst all the gear produced by the first high end company in audio. McIntosh.
you don't get the amount of haters they get unless you are really doing something right.