Mechanical keyboards are like the whiskeys of the keyboard world. They're not for everybody, and can be an acquired taste, but there's a huge amount of people who swear by them. They're also a premium product, so there is a bigger barrier to entry than the normal products.

To me, a mechanical keyboard has been brilliant. I bought a Razer Blackwidow a few years ago, and haven't looked back. It's much easier to type quickly on than a non-mechanical, because every sensation of it is so defined and fast. As a programmer, that means the connection between my brain and my computer feels more natural.

However, I know programmers that can't stand the increased sound and don't need or want the speed.

If you can afford to buy a keyboard on a whim, I would say "try it and see". The only way to know if it is for you is by trying one for a while and weighing the benefits against the negatives. Even if you don't particularly like it over a regular rubber dome or ergonomic keyboard, at least you'll have a premium keyboard that will last you a long time and will be better constructed than most.