If the D-Link DIR-865L can deliver in terms of performance, and for the most part it does, then none of this really matters. Interestingly D-Link is the first company to bring an 802.11ac USB dongle to market, the 'Wireless AC Dualband Adaptor DWA-182', so for the first time we were able to drop the frustrating router/bridge setup. It is a fatty though so be aware that if your USB ports are positioned closely together (either horizontally or vertically) it will block them off.
Still the headline news is naturally the 802.11ac performance and at our regular distances of two metres, 10 metres (line of sight) and 13 metres with two solid walls in between, the D-Link DIR-865L delivered consistent peak speeds of 26.5MBps (pictured below), 24MBps and 23MBps aka 212Mbit, 192Mbit and 184Mbit. Compared to its rivals the peak speed is beaten by both the Netgear R6300 (32.8MBps) and Linksys EA6500 (30.2MBps), but its performance at range is hugely impressive staying in line with the EA6500, which is the benchmark for everyone to date.
There is a fly in the ointment, however. D-Link doesn't state that the DWA-182 must use its own brand 802.11ac routers, but when connected to Linksys and Netgear 802.11ac routers performance dropped off roughly 70 per cent. Whether this is due to the pre-ratified status of 802.11ac causing incompatibilities or D-Link pulling a fast one we don't know, but for now or at least until firmware updates arrive, the first USB 802.11ac USB dongle should only be used with the D-Link DIR-865L and that's a disappointment.
Back to testing though and when it came to 802.11n over 5GHz the D-Link DIR-865L's performance was again strong coming in at consistent peaks of 20MBps (160Mbit), 14MBps (112Mbit) and 12MBps (96Mbit) which sees it only slightly behind the Linksys EA6500 at two metres and 10 metres. That said at 12 metres with two solid walls in between it actually set a new high beating the 10.4MBps of Linksys' product. This also places it well ahead of the 802.11n 5GHz speeds we have seen from Netgear's R6300 and the now lagging Buffalo AirStation 1750.
The problem is 802.11n performance over 2.4GHz is weak. Peaks of just 7MBps (56Mbit), 3MBps 24Mbit) and 0.9MBps (7.2Mbit) (below) were the best we achieved at our three distances and all fluctuated greatly which would certainly affect HD video streaming. Furthermore this not only falls well short of the 8.1MBps, 5MBps and 3.9MBps achieved by the EA6500, but also behind the best performing 802.11n 2.4GHz dedicated routers like D-Link's own D DIR-645 which is a fraction of the cost.
Of course as devices move over to the 5GHz band this will be less of an issue, but 2.4GHz remains by far the most common standard right now so if you have older key equipment this should eliminate the D-Link DIR-865L from your thoughts. This is a shame as D-Link has essentially got the hard part right and messed up the easy bit. D-Link is clearly aware of this problem as it has issued a firmware update to try and specifically bolster 2.4GHz performance, but our test results were achieved having upgraded to it.