I just got a used Tomos, a top tank with the A35 engine, this Summer, my first moped, and I have only put about 30 miles on it since it has been too hot to ride. Well at least when I have had the time. I got the bike used, with about 6,500 miles on it, and it showed some signs of abuse. Those signs included the pedal arms being bent from the bike being laid down on one side, scratches on the other side from being laid down, and really really bald tires. The bike is a 1991 model and had last been registered in 1993. So a fair number of miles in a fairly short time, well at least for a moped.
Anyway, all it needed to get running again was to decarbonize the engine and exhaust, new spark-plug, and fresh fuel, and it started right up. There was lots of carbon in the engine and exhaust, so I assume that it had never been decarbonized, and other maintanance items may have been skipped too. Despite this the inside of the cylinder still looks good, and it has good compression.
My impression of Tomos from this experience is that they are good solid bikes.