I used the beta before release, and upgraded to v7 as soon as it came out. I am underway every day and have an extensive NMEA 2000 network. I have 2x TZTL12F units plus a lot of other Furuno stuff + everything else on the network.
I did notice slower response in general using v7 in terms of refreshes, moving around maps, and switching modes/screens, but nothing that makes it unusable. I have seen one reboot while underway which I suspect may have been related to the reason that note was added to the release notes, but one can't be sure.
In general, while I never like seeing things slow down, the integration with v4 of TZ Pro / TZ iBoat and the other nice changes in v7 re: the fonts, reset button for a course at the top of the screen, and other general improvements are worth the upgrade by far to me.
Hopefully over time Japan can throw in a few more optimizations so that a daily reboot is not necessary.