I was looking at used 12C's a couple of months ago. As negotiations got underway, it was clear they couldn't touch the deals other McLaren dealers were offering (both on the 12C and my trade). I ended up buying from Park Place in Dallas. As far as service goes, it's been a little bit of a mixed bag for me. Luckily, I haven't had to have much done. I got the P13 update without incident. I also asked them to look at an issue I'd been having with the swipe doors (I have the double swipe problem others in this forum have mentioned). They investigated and determined this was "normal" since other cars on their lot did the same thing. At my next service, I'll push harder on getting that resolved. Anyway, certainly there's no question in my mind they are a full-fledged McLaren dealer and you shouldn't hesitate to put them in the mix as you are shopping around.
I hope you don't have Dallas doing service on your car! Two notorious cars couldn't get fixed in Dallas. Both are members here.
McLaren Atlanta when is that VP4 being delivered?