The latest versions of both OWB (v3.25) and NetSurf (v2.5) seem really quite stable on OS4. A bit odd that they were both released with about a week of each other, but I'm not complaining
They both also start fast & scroll fast, so I really don't see a need for the aging IBrowse now.
P.S. I'm sure that *someone* still has problems on some site or other, but I think now is the time to start adding new features. (NetSurf is a bit ahead of OWB in this area, but I guess that wouldn't take much to change.)