I don't think locked bootloaders would be a problem - Samsung's been pretty generous with regard to hacking their devices (huge rootfs space, kernel source, unlocked bootloaders, etc.)
Not so much regarding speed of updates and Touchwiz (which even version 4.0, tbh, looks cheap), but they do come eventually.

The problem I have with all smartphones (GNote and SGS2 included) is that the tiny battery simply cannot keep up with the powerful SoCs and bright screens they put in them. The recess on the back of the SGS2 shows that they're putting extreme thin-ness above all else. I'd gladly trade 2-5mm more thickness for a more battery capacity.