As Balu has written I would say any stars not round are due to guiding or not correct distance of the chip to a reducer/flattener. Bloated stars would catch my attention if I were looking for optics that are not up to AP.
Really helpful thanks. Those stars are much better than a lot I have seen. Interestingly I started looking at the WO FLT 132 this morning and there are a lot of good images online taken with it.
The LZOS has great resolution, the small star next to Altinak in your horsehead is nicely resolved - its not even visible in my Esprit 80 image (I know they are not really comparable).
I would be happy to produce these images so both scopes are good. The WO works out about two thirds the price, inc reducer, but I do like the F4.5 for faster imaging.
Don't know if you can help with this but I bought a 102 in March and sent it back because I couldn't get anywhere near round stars - which is why I'm so worried about it now.
I had spot on focus using a bahtinov mask and assumed that if it was in focus the spacing would be ok for the flattener.
I'm wondering now if it would have been possible to improve star shape by changing the spacing within the focus range. I don't know how much you can change spacing and still keep it in focus - is there some room for adjustment here that might have got the reducer working? The manufacturer was very supportive when I reported the problem and asked for advice, but just they sent a new focuser and reducer out and didn't suggest that I try further tuning.