I did go and visit the handmade kitchen showroom and I have to say I was a wee bit disappointed in the quality. In fairness, one of my peeves was with the paintjob which I found sloppy (they had painted them all with the doors on - so it was messy round the hinges, etc). Obviously this is irrelevant as they only supply them unpainted so as long as you have an awesome painter, it should be fine although I cannot conceive why they wouldn't have their showroom examples done up perfectly!
But the real nagging issue for me is that the actual open/close of the cupboards I found to be a bit "homemade" feeling. I am used to cupboards that close softly and with a nice magnetic latch at the end. With HMK you can choose between magnetic latches or old-school clips but either way, they just felt flimsy. The drawers on the other hand were lovely and opened and closed like a dream.
I had been to see Kit Stone and really loved them but thought HMK would be practically identical - it isn't. However, the advantage to HMK (besides cost) is that you can get units totally made to measure so absolutely no loss of space. Note that Kit Stone kitchens are made by Neptune (KS are basically a reseller) so if you want to do more research, google Neptune as there is quite a bit more feedback on quality, customer service.
The next spanner in the works is that I have found that Costco (!) sell a painted kitchen that is also made by Neptune and looking at the site it is really lovely and the prices are amazing. I have a spreadsheet comparing HMK, KS and Costco and the Costco is the cheapest (once you include cost of painting the HMK). Costco comes painted and it seems like you have no choice in the colour (cream). I would rather a grey/stone paintjob but it might have to be a sacrifice I have to make for the budget esp if I can get the same quality units as KS but have more in the pot to get an amazing worktop, cooker, etc. Have a look at the Costco one here www.royalkensington.com
I am going to Costco on Friday to have a look so I will report back! Also, HMK's "sale" is ending on Friday and it may be weeks/months before they revert to their 50% off pricing so if you are going with them, you should call up and give your £250 deposit to secure those prices if you need the kitchen in the next few months.