Most of the buying experiences I hear about HC are pretty lukewarm, whereas most of the things (buying *and* service) I hear about MoP are good to great. MINI has largely built their brand around being able to customize (or "you-i-fy", in their parlance) your car to the nines. I personally be wary of any salesperson (aka "Motoring Advisor") who tries to sway you from ordering exactly what you want. From what I've seen, most of the cars on the lot are over-specced, and way more expensive than what I would personally choose. I haven't looked too closely at what MoP keeps on the lot, but the dealer in Indianapolis had no shortage of $28,000 Cooper Ss when I lived there. I think MoP does it pretty much the same way. If you can find exactly what you want on the lot, cool, but otherwise, order away!
I don't think you'll find mark-ups or discounts at either place. California had a lot of that going on, but not so much in saner parts of the country.
I bought my 2nd MINI from Hrach at MoP. He's a great guy, but be prepared to stay awhile if you give him the chance to talk!
