boyfriend is getting on my way

You sound fairly young, but in time you will learn that men are always right. by all means listen and believe your boyfriend or any man for that matter. you are very welcome for this good advice. and good listening to your music too.

Speaking only to the issue of the amplifiers, I will offer that I auditioned both the Bryston 4B-ST and the McCormack DNA 2 in my system before eventually buying the 4B-ST. In my system, I preferred the sound of the 4B-ST, and I also like the fact that Bryston gear has an unconditional 20-year warranty (I have a strong value orientation toward audio gear) and unsurpassed customer service. McCormack is now owned by Conrad-Johnson, which means it is financially backed by one of the established names in high-end audio, although Steve McCormack still heads the development of the amps bearing his name.

I'm sure your boyfriend means well, but before I'd swap out the 4B-ST amp, you should audition the McCormack in your system. One thing to bear in mind here is that women generally have more acute hearing than men, particularly as we get older, so what you hear may be different than what your boyfriend hears. Don't make a final decision about your amp based solely on someone else's opinion -- as I have often said on this forum, "trust your own ears".

Well, you should know better than to ask a bunch of (mostly) men whether you should listen to your boyfriend. :-)

It sounds to me like your boyfriend wants to play audiophile while spending your money. That's probably not worth divorcing him over, although he may become more of a nag if you resist. In that case, all bets are off.

As for the amps, The Bryston's a great piece, and I don't see a word in your post suggesting that you are at all dissatisfied with it. Nor do you sound like the kind of person who enjoys changing your system around just for experiment's sake (or the fun of it). So don't.

(If you really want to drive him crazy, tell him you've decided to become an objectivist, and you now believe all amps sounds the same.)

Don't even consider switching amps unless you can A-B them in your system in your home. I doubt very much the DNA-2 will make much, if any difference, and it may not be a difference you enjoy. Tell you boyfriend to buy a DNA-2 and put it in his own system if he likes that make and model so much.

"trust your own ears"..... Sdcampbell said it perfectly.
It's your system, your money, your ears and your choice.
You MUST always audition the piece of gear in your system before you buy it. This is the only way to buy.After all isn't it YOUR system.
If he wants you to have a different amp in your system have him buy it for you.
Just my $.02, Rick