I am also using the C2300 with 12AX7 and 12AT7 Telefunken smooth plate on my 2xMC275-V. I don't like to mix anything. The bottom line is wonderful sound with no limits. If I need to upgrade, my system will be C2500 to match MC275-VI or C1000 to match MC2301 only.
With your older MC402 and MCD500, I would recommend MC2300.
With your older MC402 and MCD500, I would recommend MC2300.