Okay, I will jump in.

Well, it all started with a strange desire to buy 4x5 camera about six years.
Then about five years ago, I decided that 4x5 wasn't enough and upgraded to 8x10.
That kept me busy for a while, but after a while 8x10 contact prints were beginning to look a little small.
And finally the 12x20 arrived about 4 months ago. I haven't had time to get it out as much as I would like, but it is a true joy to use.
Maybe at some point 12x20 will seem small and there will be a need to go to 20x24, but I don't see that happening any time soon. The bank account nor my wife will allow that for some time to come.

Its a dangerous slippery slope we are on!!