NAD M3 or parasound classic 2100 and 2175

You have convinced me I need to upgrde from my NAD 352 driving Tetra 120 monitors and velodye sub. (see my post under preamp or new integrated) Love the speakers and my Cyrus 8x CD unit and I don't want to change them.

I was thinking that the Parasound 2100 would help because I can tell it my speakers are small and it will cut frequencies below 80 Hz. I know this will inprove the sound subtlely but meaningfully--I used my NAD 747 HT reciever to demo the concept and i immediately heard an improvement (of course it is newer and better than my 352 in other regards too). And I see I can do the same thing with a NAD M3--a little old too maybe, but i can get a good price on a used or refurbished unit. I think the new HK 990 will do this too, but let's leave that out of the equation.

I think I am down to these two solutions-- I just like the idea of NOT sending the bass signals to my monitors. Improves details and soundstaging, I believe.

So, the NAD M3 or the Parasound 2100 with a new 2175. Cost will be about the same, probably more for the Parasound by the time I buy another set of Hero ICs.

Your thoughts, and as always, thanks in advance from this long time lurker.
There is a lot of info on the M3 here and in other reviews online. It was a Stereophile Class A component if you care about that. I happen to like mine and I have owned equipment from BAT, Rogue, Rotel's top of the line, W4S, Nuforce, and Parasound JC1 amps to compare to. Revel, PSB, Usher, and Acoustic Zen speakers as references. The M3 is good but it is mostly about synergy with your other equipment and room, and your ears and sound preferences. I used my M3's bass management feature with Usher BE-718 monitors and a pair of JL Audio F110 subs and it worked great. Now I'm running it full range with Acoustic Zen Adagios because they don't need the protection of a limited bass signal. The NAD is smooth and rounded off at the extremes a bit and that is one of the things I like about it plus it is fat in the middle. It still has detail and good soundstage width and depth. It matches well with my Adagios and it did with the Ushers, too. I'm not familiar with Tetras (except for the freshwater tropical fish-I have a bunch of them) so read whatever you can and take your chances if your research sends you in that direction.