So here's the deal... My home network starts with a Time Capsule 5th gen (ac) connected to 200 Mbit fiber. A bunch of iPads and two iPhones are connected via a/n. Also, a MacBook Pro (a/n/ac), a Mac Mini (a/n) and an old 2008 iMac (b/g/n). Signal quality is reported as "excellent" all around, -44 to -52 dBm. The TC is smack in the middle of a 900 sq ft apartment, I can't go farther than 30 ft from it in any direction so the signal can only be excellent really. The MBP connection speed varies between 877, 1053 and 1300 MBit according to AirPort Utility. Running internet speed tests I manage to squeeze out 160 Mbit/s which is WiFi speed I should be happy with. Running the same tests wired (Time Capsule bypassed) it maxes out around 180 Mbit/s. Problem was, the Mini is my media server and it managed only 60-70 Mbit/s. The old iMac (with g speed only), much worse, around 20-25 Mbit/s. I couldn't run an ethernet cable from the TC to the room where the Mini and iMac are, the installation would just look nasty. So I thought I'd extend the network with an AirPort Extreme 5th gen and wire the Mini and iMac to it so they could enjoy full ac speed. It worked out pretty well. The iMac and Mini now manage 110-130 Mbit/s. However, once the AirPort Extreme was introduced, the MBP is for some reason hell bent on clinging to it instead of the Time Capsule. And once the MBP connection is relayed via the Extreme (which is ridiculous as they're around 15 feet apart and would probably still report excellent signal if I was across the street), internet speed for the MBP drops from 160 to around 70-80 Mbit/s. Much slower than the Mini and iMac since they're ethernet-wired directly to a strong WiFi transmitter rather than having their WiFi signals relayed via one. Once I unplug the Extreme, the MBP merrily snaps back to the TC and 160 Mbit/s. Within minutes after I plug the Express back in, I find it French kissing the MBP again and internet speed is cut in half. 1) Is there any way to lock the damn MBP to the TC? 2) Also, since I've given the 5GHz network a separate name and connected the MBP to that network alone and made it blind to the 2.4Ghz network, how is it possible that AirPort Utility still occasionally shows that the MBP is on b/g/n rather than a/n/ac? b/g are 2.4 only. 3) Why is it that AirPort utility sometimes report that a device is connected via WiFi to both the TC and the Extreme? I often find 2-3 duplicates in the lists. AFAIK a single wifi adapter can't be connected to multiple base stations simultaneously.