No one has mentioned it; but what preamp do you have?
You really need to try Pass X1 preamp or something at that level before changing your amp out.. I find the preamp can provide one of the largest flavoring or clarity controls.. If you haven't heard a premium preamp you have no idea what you are missing. Also make sure to run Balanced as my friends X1 really sounds better with XLR inputs and outputs because of the fully balanced design.
Since you have VR speakers you probably like to listen with a little volume, try to go to the 501's instead of the 402 if you are a bass head.. The MAC 402 uses a parallel design versus the higher end design in the 501 and the 1201 amplifiers and keep in mind autoformers don't double in power as impedence drops so your X250 has more 4ohm current than the MC402, and the MC501 are a different design.
One of my friends owns the MC402 and loves the look and flavoring and even more so with the latest Mac Preamp.. His system has very good synergy and the Mac gear tailors to his musical preferences..
Between those two choices I would lean towards Pass X250.5 or an X350.5 since more power never hurt anyone. I have a friend with VR 4 GEN III SE and he uses a pair of Parasound JC-1 which have insane control over his bass modules, and the adjustable Class A bias (10 or 25watts with a switch) he enjoys. The Parasounds need 1200+ hrs to break in but are a bargain in my opinion.
Oh yeah don't worry about how many are for sale, audiophiles are just obsessive... there has to be something better right ;-) how many of us have upgraded and ended up moving backwards... The good thing about Mac gear is the dealers don't discount much so the prices on the used market stay high so you can always turn it.