McIntosh MC402

I'm a 402 fan and long time owner. Always listenable, clear, and liquid. It has a decently low noise floor. To get the most dynamics and transparency you need to experiment with  preamps. I got very good results with the Hegel p20 and p30. The 452 is known as neutral where the 402 is slightly warm. As usual, the rest of your system is key for getting the most out of it.

The 402 has more of the McIntosh classic sound whereas the 452 is more neutral. I've owned both and in my system preferred the 452 with Sonus Faber Olympica 3s. 

You would probably be happy with either.  I have enjoyed an MC452 for several years, originally pairing it with a C50 solid state pre-amp, changing that to a C2500 tube pre, enjoying the slight difference in "musicality" the tube pre offers.

My only opinion about going with a C402 is to consider that it's X number of years older and will likely need to have those parts that wear over time (like capacitors) replaced sooner.