Vivian is the only 8.1 model in the lineup, and she definitely caused me a lot of pain until I upgraded the RAM to 32gigs. She still takes longer to render than the 8.0 models, but at least things aren't freezing and crashing all the time anymore. I'm running everything on my fancy gaming laptop: it's fast but can't keep up with a comparable desktop. Not sure 8.1 is terribly worth it over 8.0 to be honest. Especially since I have a lot of 8.0 models I already bought that haven't even been put to use yet. Then again it's kinda hard to stop the inevitable march of progress.