I got a quote for a spinnaker recently. They intended to use the very same cloth as the UK lofts and were very much cheaper £450(ish) as against £850 for the dearest UK job.
However the size was one of the smallest and they didn't answer my specific questions about the design of the turtle, nor whether it was a full-radial or just a tri-radial with the usual central vertical section, so I went to a well known UK loft, offering 15% discount and thus got the largest(54 sq.m) full tri-radial kite for a very good price £650.
If price had been everything I would have given HK Sails a try- Did I do the right thing? Only time will tell
I have a main and genoa from HK Sails. Now in their third season, and looking good. One in fact deals with a chap in Plymouth, not direct with HK. He will make sure you take/give correct measurements. Delivery was quite quick, as far as I remember.
I would have liked longer battens and slightly different distribution of slides. Also, the clew reinforcement of the boltrope could have been stronger. But basically I'm a satisfied customer.
Price was the guiding factor. It was far below UK quotes.
Had an excellent main supplied by HK sails 2 years ago for a Macwester we had. Just under half the UK price and first rate quality. Very helpful measuring assistance and fast delivery.