I agree that the Banshee is to blame for "not perfect" emulation.
However, I don't believe that the Banshee, which may not support certain features that PJ64 and others use, is insufficient to make it at least playable.
In other words, I'm not expecting to be blown away with huge numbers of FPS and extreme superiority in graphics when I get it running, as I realise the Banshee is really old. However, I did, and still do, expect that the Banshee is able to handle the emulation, even if not at full speed, then at close to full speed, with the correct or at least acceptable graphics. And hey, I'm a guy who doesn't care too much about graphics (just think about it, the fact I've still only got a Banshee!) so when I say graphics is bad, I generally mean it's not playable...
In short, all I'm trying to do is get it to a playable stage, and I don't think that is beyond the banshee, although it is four years old or so...
After all, there are guys here who have said they get great FPS with much older hardware...(Some with MUCH less RAM and lower CPU, but admittedly a GeForce... However, I seem to recall some of them saying they have a Voodoo 2 with a approx 700 MHz P!!! and it still works fine for them, albeit slowly (top 40 FPS)...