Launched in October, the latest editions of AirPort Extreme and Time Capsule are causing performance problems for some users, who are already gathering complaints in a topic on the company's support forums. Apparently, transfer speeds on the two Wi-Fi bases are extremely low when configured on 5GHz networks, making it difficult or impossible to use them for web access, file transfers and backups.
In certain cases, the speed of 5GHz networks in Time Capsules and AirPorts Extreme is even lower than a 2.4GHz connection, by a huge difference. Theoretically, your hardware should deliver a 50% increase in performance when compared to a conventional 5GHz network, in addition to offering 25% more space than the maximum standard distance.
This is not the only problem affecting Apple's Wi-Fi bases, as many users have already reported deaths from Time Capsules within relatively short periods. Himself market share of Apple in this area has been falling a lot in the last months: in this segment Apple is in fifth place, behind Linksys, Belkin, D-Link and Netgear.