It's not the best phone in the world, people who need a good camera or video functions/turn by turn GPS/fully functional exchange integration should look elsewhere. However if you don't need those functions right now and can wait then the software will become available to allow all but the camera issues to be resolved.
As for MMS it's easy to explain. Pick up phone, call iphone team, tell them you have installed a 3rd party application to allow MMS, you've tested it with a friends contract sim who's on a non iphone tariff and you now need them to add the MMS service code on the back end provisioning system, you don't want any support, just the service code adding, it's a non chargeable option. If you want the full spiel have a look at my post on the subject including the settings required to make it work with the iphone on this forum a few weeks back. Back when I did it they had pulled the app store mms offering but i'm sure someone said it was back now, either way they'll put it on. If the first person won't just ring back, took me two attempts by phone
For forwarding texts and a conventional SMS system (inbox, outbox sent and drafts etc) use iSMS. Also 3rd party apps give copy/paste functionality. So that aside it leaves the camera being a weak spot, potentially the battery life (try running a tomtom for 24 hours on a single charge) and the cost of the handset.
The crashing issue is normally the user directory privileges, again it's a one click fix with Boss Pref's taking all of 10 seconds, it normally happens in mail or safari from personal experience but others have reported other standard apps suffering. Once done i've not had a problem in weeks.
To be fair on paper my XDA Orbit is a better handset, and with custom rom's it was good but after a month of using the iphone I went back for a day and realised how basic it actually was even customised. The reality is the usability and integration of the iphone UI/apps is vastly superior. The OH doesn't want my old one so she's picking up her Omnia today but it'll take a lot to convince me to go back to WM.