If you specifically don't want to have to sharpen the knife yourself I wouldn't recommend the Sebenza too much. Their steel is very easy to sharpen if you have experience and the rigth tools, but it will not hold an edge for a really long time. Sebenzas are excellent for users, and especially in the field, but you do need at least a small strop and an ultra-fine stone.
I will second the 0550 though. Will hold an edge better, is built very well, and both of the ones I've had have been some of the smoothest knives on washers I've felt for less than $300!
Honestly though, I would recommend a Benchmade Ritter Griptillian, as long as this isn't specifically you looking for a Ti Framelock. They now come in M390, which will hold an edge insanely well for you, are light, come in 2 sizes, and have a sharpening service through BM. Also quite a cost-effective knife, with a good strong lock. I know it's not a frame lock, but honestly I don't think you lose anything in the knife.
If you're specifically after a framelock, and you have a higher budget (not entirely sure), then I think the Strider SNG is a good choice. I have always regretted letting my SNG go, and I will be getting another one, because I just loved that knife. IF you do get one, I would sasy to try and find one in CPM154 instead of S30V. S30V tends to be more prone to chipping than CPM154, and I find that Strider's CPM154 holds an edge longer than their S30V. You would have to find someone to professionally sharpen that knife to get the best out of it though either way.
Lastly, I would recommend the Diskin Fire. It is a discontinued knife that was a custom, so you may not find one easily, but is has a Ti Framelock with steel insert, Elmax steel treated very well, comes in both a manual and dual-action verson, and has both Ti and Carbon Fiber on the handles. Works great, has a spectacular edge to start, and holds it like crazy (not quite as good as M390 though

).
I'm more scewed to higher-end knives, so I probably forget a few...