shows 4870 at 104.6 MH/s with -w 256 -f 1, Windows 7 64-Bit, GPU Core OC to 830 MHz, GPU Memory UC to 190 MHz (saves 30 watts at outlet)
Might want to try that.
As far as if it's worth it, try calculating ...
1) how much bitcoin do you get / day? Keep in mind the current exchange rate, the last I check was USD12.xx / bitcoin .
2) how much electricity did you use?
3) 16 shares out of ?? What's the total number of shares for that block? When you mind in pool, the 16 shares just mean, you get 16 shares out of x number of shares for that block. So, say 10000 shares for that block, you will only get 16 /10000 * 50 = 0.08 bitcoin.