Personally, I think new products come about due more to sales and marketing, and less to the need for technological advancements and competition. There are certainly things that lead to new innovations and products, for example the brushless systems, however most of the time 'new designs' are simply things to keep the cash flow in the door. Let's not forget what these companies main goal is, money. Not that I blame them, they are in business to make money.
If you want to buy a new buggy to have the latest 'greatest' thing, then great. Knock yourself out. However, if you are on a tight budget don't fall victim to the marketing schemes that you have to have the latest to be the best.
Often the pros switch to newer products, not because they can't compete, but rather because they can get a new vehicle for little to no cost. Why not? The pros are pros because they are paid to sell new buggies. Don't forget that =)
Just an opinion.