I'm no expert but I have a V6 Mercruiser I/O and it has 4 block drains and I can drain the block and disconnect two hoses (that are on top and easy to get to) to dump a little non toxic anti freeze down the thermo housing and in less than 15 minutes we are good. I did it twice this year back in Jan. or Feb.

Simplicity of Winterizing should not be a deciding factor IMO.