They all have there pros and cons. I had a TMC electric for 3 years and it was perfect the entire time. We used to have a manual one on our boat as kids (20 years ago) and it was faultless apart from a service every once and a while.
cisco said..
Does everbody here actually know how to operate a marine dunny............??????????????????
You dump then you pump. You wipe then you pump, if necessary, a couple of times over.
I hazard a bet that I have unclogged and repaired more marine dunnys, both manual and electric, than anybody on this forum.
Dump, pump, wipe, pump i might have to use that one sometime. Unfortunately some non-boating visitors prefer to use it like a house toilet dump,wipe then try and pump the whole lot out at the end

. Even if i tell them not too ):
After they leave im left with the messy job and i end up covered in piss and sh!t weilding my weapon of choice.. the humble yabby pump

.