Most of the problems can be fixed. The settings disappearing can be fixed by installing a custom mobileconfig from the help.benm site with the MMS settings (APN, user name and password) in place of the data settings and tethering enabled, rebooting, then changing your data settings back. I won't go into too much detail here as it is Swirly's forum, but a little digging on the sites I linked should be able to fix everything up, including small picture issues that some may have.
Once everything is set up right, it works just like on the 3G. With the frequency I use MMS, which is to say not much at all, I much prefer it being confined to my Messages app (in my case BiteSMS, which is fully compatible with MMS features when enabled) rather than a whole separate app and icon on my home screen. The way messages are received is much more fluid and integrated also, with the picture popping right up in the message notification, and with a click-able thumbnail in the conversation window.
Don't get me wrong, I think Swirly is great, but I just don't need that many features, so wasn't willing to pay the upgrade price while other options were being explored by the hackers.