I don’t know personally either. I’ve been doing some research to get a FW13 to put Linux on it, and from what I can see the biggest battery life issues are due to standby power management in Linux not being great. It looks like “fixing” that requires jumping through a lot of not-so-well documented hoops. I’m still not sure about battery life differences under load.
If it’s just hibernate/suspend not working well, I got used to that with a work thinkpad I had with Ubuntu. For my use, it was a little annoying but I was happy to deal with it because I could daily drive Linux
Enshittification at it’s finest!