I wouldn't mind switching to microb. Some things work better in microb than in Opera.

However, the reasons I have not switched yet are, in order of priority:
1) No easy way to configure microb to use the dpad as page down/page up. This is the real killer for me.
2) The optimized view works better in Opera than in microb.
3) Microb is noticably slower in startup and on some pages. As this is a beta I expect this one will improve over time.

But 1) is just the clincher for me.