I've tumbled several hundred bottles and never really noticed any change in my electric bill. (I always wondered about that myself before I first got started.)
Looks nice, but a little over-tumbled. It's too smooth looking, and the already weak embossing looks tumbled smooth. It's lost part of it's historic look and texture. Honestly I'd pay more for the uncleaned version.
Tumbling not for everyone, some like it some don't. The embossing is still pretty big & bold but it will flatten the top of the letters. This bottle was heavy duty scratched up & beat & needed a heavy duty tumble to get the big scratches out. I prefer a bottle that's more stained & dirty & needs a light tumble. Those always come out better & look more original. LEON.