consider how you will use the piece in regular listening. For me, I like to roll tubes so having easy access with exposed tubes allows for me to do this without a major disassembly process and moving the components, wires etc. Having the ability to put the tubes in standby or bypass mode is also very nice if you are a 24/7 power on listener. While some chime on about difficulty in locating them, I find the 6SN7 NOS tubes very pleasing to my ears
very much agree with the above - good luck