Adding It All Up
In the battle for bragging rights to the largest 802.11g throughput number, it appears that Broadcom and Linksys have blinked. Though both companies continue to beat the "good neighbor vs. bad neighbor" anti-Super G drum, they now talk % performance improvement, not absolute throughput. Linksys really seems to have gotten religion - or something else - about backing away from using throughput numbers, since I couldn't find a reference to any Mbps specs (not even 11g's normal 54Mbps!) on the WRT54GS or WPC54GS' product boxes.
In all, I think this is a good thing, because the usable throughput available from any wireless products can never approach the raw data rate due to the extra overhead made necessary by the inherent unreliability of a wireless link. Where the value really lies is in getting the best speed over the widest range, and that's where the WRT54GS / WPC54GS fail to impress.
As far as the question of whether Afterburner or Super-G is "better", the answer for many (most?) users is probably neither. The only users who will get the maximum benefit from "enhanced" 802.11g products are those who:
a) Are willing to buy / upgrade all parts of their wireless LAN with products using the same enhancement technology, from the same manufacturer
b) Make sure all parts of their WLAN are operating as the same, latest, firmware and driver revision levels
c) Don't have any 802.11b WLANs within range
If you don't meet all three criteria, the premium you're paying for "enhanced" 11g products is just money wasted, especially if you have 11b WLANs in range. (Street pricing at the time of review puts the premium at about 20% for Linksys' GS vs. G router and CardBus card.)
The bottom line is that if you liked the WRT54G / WPC54G, you'll probably like the WRT54GS / WPC54GS too. Just don't buy it because you think it'll be significantly faster, because under most real-world conditions, the extra 20% spent will just get you a GS on the nameplate, and fewer blinking lights on the front panel.