The old experience was much more comprehensive as you could book travel with a promo code (any code) and credit it to your ACfB spend. With the new program you have to use the specific SMB promo code to credit the spend to your corporate account, although the discount is slightly larger. That said, we'd sometimes pair a promo code with an ACfB booking. The MLL pass and eUpgrade credits from the old program were also nice, although I can see how bonus Aeroplan miles for employees for each booking are probably a better option.
Although underwhelming, the shift makes sense. Having two completely different (but similar) flight booking experiences was likely quite expensive. There were quirks too, like pricing on the ACfB side being much higher than the B2C site on occasion.
One benefit that was useful for our people without status is that ACfB customer service was much easier to get in touch with than the traditional B2C customer service.