closed as not constructive by Ben Brocka May 15 '12 at 18:17
As it currently stands, this question is not a good fit for our Q&A format. We expect answers to be supported by facts, references, or expertise, but this question will likely solicit debate, arguments, polling, or extended discussion. If you feel that this question can be improved and possibly reopened, visit the help center for guidance. If this question can be reworded to fit the rules in the help center, please edit the question.
I think what you're looking for isn't a feedback website where the person doing the reviewing only really has access to a screenshot or something similar and can therefore only really review that, but a full-on performance, usability, design and accessibility expert review. I doubt you'll find a site where people are willing to do that for prices like $99 (which is what conceptfeedback charges for 1 expert's feedback). For comparison, my company charges hourly rates and expert reviews usually take 2 days of work (at least), so that could easily cost several thousand USD.
Perhaps you should adjust your expectations, or hire someone to give you professional, in-depth feedback :-)
You might consider uTest, which claims to offer usability feedback from 'professional' testers.
You may also consider sites such as userlytics and usertesting.com, although, as ever, the results you get from crowd-sourced usability testing will be determined by the questions you ask, the types of tests you compose, and the demographics you pick.
I agree with Rahul, you can't really find that support in a website because the things you want to check align very much to usability issues which can't be measured properly by an algorithm. Decision about when to use drop-down and when to use radio button have to be decided by case in addition to the partially technical feedback you need you should consult a usability expert with technical background to make an expert review of your website. If you want to do it on your own and want to structure the way you evaluate, you could have a look at the ISO 9241-110 http://en.wikipedia.org/wiki/ISO_9241#ISO_9241-110. On part of it is for example, to ensure conformity with user expectations.