Likewise. Last year I got a quote from the "recommended" insurer on the Diabetes.co.uk website which was way more than any standard insurance company. I chose a Sun Alliance quote from my local broker, which covered all non-diabetes related claims for the whole family, which meant that "normal" things like broken bones, delays, cancellations etc. were covered within their standard quote.
recently requested a quote from the insurers that this site promotes. They refused to quote, but refereed me to another "specialist" insurer who did quote me for diabetes cover - at over twice the price I was quoted by a "non-specialist" company, even with diabetes cover. Given that the non-specialists had quoted in excess of £800 just for me I was not impressed with the specialist "understanding of my illness". Add to that the fact that they would only cover me in the event of my claim (ie. not for the whole family and therefore the family could not cancel the trip if I became too ill to travel), the £1700 quote was a bit ridiculous. Perhaps this is the next area of the insurance business that should come under the "discrimination" spotlight.