When an airline offers the new Biz class type of product they usually do so by making this product their only premium cabin. Therefore you are getting that carrier's best service and best seats. Therefore, the new Biz class usually gives you the same type of service in terms of food and attention you would expect in first class on three cabin airlines. And since you are in the front cabin in the new Biz class there is nothing better that you can buy or upgrade to so you do not feel as though you are missing out on something better. Yet, when you fly Biz class on three class airlines you never quite feel you are getting the best that airline has to offer.
However, where new Biz classes fall short is in the seats themselves compared to first class on three class airlines. There may be a large comfortable seat with plenty of room in the new Biz class products, but since the three class airlines are installing suites and beds in their first class cabins the new Biz products can not match that level of room and comfort.
Specifically, Continental's BusinessFirst is a great product with great service which is far superior to the old style biz class on three class airlines. It seems to win a lot of praise and awards and deserves its reputation. It is really a first class product.