ED5 It may be a bit late but here is my opinion of Dolphin, relative to your question.
Dolphin is probably as solid as any other software that you are likely to come across.
BUT... and it is a fairly big but.
before you can relax with a Dolphin site that does what you want it to do, there will be a load of fairly complex work making it behave in a predictable manner. Most of what you will need to do is posted right here on Unity, but it will take quite a lot of time and an increasing knowledge of the codebase to actually find the fixes that have been thoughtfully worked upon by the community.
How that equates to money is a matter of opinion, I have kidded myself that I have saved a small fortune by spending months getting to know the code (I am still only scratching the surface). But if I had paid myself my standard day rate for this invested time, I am sure it would have worked out far cheaper to farm it out to someone that knows boonex inside out (I wouldnt be paying for the learning curve).
Though this may seem to be a matter of economy - looking back, I have actually lost quite a lot of other work and chances to develop the profile and advertising of my site, because I have had my head stuck in the labyrinthine code that makes Dolphin tick.
So I would say that if you are serious about building a business on the back of Dolphin - farm it out to someone knowledgable about Dolphin (perhaps someone here - not a programmer that has never worked with dolphin), and devote your precious time to what you do most efficiently, whatever that may be. That way you will get the best value out of all the effort that is expended on your site.
and, by the way, Good Luck.