from Topre to G80-1800, you've got to like Cherry switches. Seems most Topre folks will never give up their topres.
I personally had an 1800 and did not like it at all. Remember, the right hand side is just one huge undifferentiated matrix of keys. This makes it surprisingly hard to get your page up, or your delete, or your numpad asterix/ multiply sign correctly typed.
It took me a lot of effort to get rid of the 1800 and I don't have one to sell anymore. Was a trifle disappointed to find that geekhackers value the 1800 so much - after all, I no longer have one to sell!