Thanks guys.
The astrobin pic is a crop - I ran 3x drizzle in DSS, which limits you to only processing a small section of your image. It's also not from the center of the frame, so I think coma is most or all of the trailing/eggy stars effect. I have an MPCC on the way, so that should hopefully help.
As to polar alignment, my sky view is a bit limited so I found alignmaster to be difficult. I quite like the PHD approach, but I have found it can jump around a bit (seeing perhaps?) which makes adjustments a bit difficult. Also once you are less than about 1 arcmin of error on an axis, the guide circle on the image is really small, at least with my setup. I was wondering whether I could be chasing periodic error, so I was interested in programming the PPEC in my mount, but I'm not sure how. I did take a first series of shots in this session where PHD disengaged for some reason and there was some trailing, so the polar alignment clearly wasn't perfect.
Oh yes and I haven't taken any flats or darks. The noise on the camera seems okay, so there hasn't been much of an issue with hot pixels (unless I really stretch the data), but I do think I need to work out some flats.
I did check collimation just before this session and I think it was pretty close. I spent a fair bit of time setting the scope up when I got it and think it's okay, though having someone with experience look at it would help too. I used my old collimation kit from 15 years ago, so there are no lasers
I'll take everything you've all suggested on board and apply it the next time I get out to do some imaging. Was hoping it could be this weekend at the ASV dark sky site, but the weather isn't looking positive.
I think my ultimate destination will be narrowband, but I might have to pay the house off before I get that past the finance minister... I'd also like to do some more longer focal length stuff, but that's something to look forward to as well.