Actually, Karnak...X-ship on X-ship is often quick and quite brutal. I think it's a blast. I wouldn't wish to make a quality statement on the comparison of X-ship combat vs. SFC3 combat. There are some distinct similarities, but cruising around at high speed all the time in either one really isn't a great tactic. Sure, you can do it....but neither one guarantees a win.
I think those that prefer the SFC2 milleu will prefer x-ship combat over SFC3, and visa versa. I think FireSoul's addition of SFB-style x-ships will breath new life into x-ships on the Dyna, though they are, as yet, untested to my knowledge. I think SFCx's "Tech Wars" server will increase the data we have on that account.