It depends on how you work. I have a pretty good company laptop, but it's pretty much just a front-end for an SSH client, a web browser, and a local Windows VM. All my actual work happens on remote machines.
The headset must (requirement) be stand alone. You can’t have an 8 hour runtime on a stand alone headset with an i7. They have to go ARM
I just finished a 6 hour session on the OC2 with the elite strap w/extended battery
No currently available headset has a 8 hour runtime. Our target is 3 hours.
I don't work for 8 or even 6 hours continuously without breaks. For me 4 hours would be ideal. I guess 6 would remove any "range anxiety"