I don't remember where I first heard it (a Google search suggest's it originated with Tony Soprano!) - but I've long been a believer in the maxim: More harm is done by indecision than wrong decision.
All too often people are looking for a perfect model, to be 100% confident they're doing the right thing before they do it. But we live in a complex system with too many variables. You can never be 100% confident in the success of anything. All you can rely on is your own experience, and often nothing more than gut feeling that you're making the right call.
If it's a choice between two or more options, and you're in a group where different people are arguing the case for different choices - chances are, any one of them will be a good choice. The important thing is to get started and get everyone fully behind it. Looking from my own experience in web design, not everything on a new site will be perfect immediately. But finding a few bugs in an otherwise improved website is better than living with a deprecated site while you do endless testing and refinement on the new site, delaying launch.
Whatever you're working on, part of the workflow should be to make it public when it's at 95%* and accept the best way to perfect it is with real world feedback.
* 95% is plucked from the air - and should be determined on a case by case basis. If you can get away with it, launch even earlier and put an alpha or beta sticker on it.
Again, in the case of anything online or digital, the nature of the medium makes it easy to push out updates. It is also even more necessary to launch early and test because of the amount of variables between technologies out of your control involved in the process.
Yes - if something's worth doing, it's worth doing right, but don't be afraid of not getting it right immediately. It probably needs to be at least OK, or better yet good - but it's unlikely to be great straight away.