The cheapest advice I have for you is to stick with the 510 and get two more batteries, a PCC and a USB passthrough. That stuff isn't very expensive but it'll make your experience with the 510/Titan MUCH better. There's no doubt that the worst part of the 510 is its pathetic battery life, but with a PCC the battery life doesn't matter. Just swap for a fresh one whenever the one you're using runs dry. I have three batteries in constant rotation, and I think that's a pretty optimal setup. I'm never in a situation where I don't have a fully charged one on deck. Three isn't that many to keep track of, so it's a reasonably efficient work around for the short battery life. Plus, a passthrough will free you from messing with batteries for at least some percentage of your day. I use a passthrough at my desk and batteries when I'm driving around town. If I had a cigarette lighter passthrough (ironic!) I'd save even more battery life.
So, to echo what everyone else has said, because you've made the basic investment already, I'd strongly advise sticking with it a little longer. Spend a few dollars more to get your 510 setup rounded out and I think you'll be very happy with the results.
So, to echo what everyone else has said, because you've made the basic investment already, I'd strongly advise sticking with it a little longer. Spend a few dollars more to get your 510 setup rounded out and I think you'll be very happy with the results.