I've been playing around with this device. What I've noticed so far is that using this patch to disable usb3 doesn't do that much to improve wifi speeds. I think the most impact has the fact that folks have been working on the opensource driver:
If you're following LucyLight's advice you will indeed get the latest drivers in - however the same can be done by flashing the latest snapshot.
I've done some tests (not conclusive might i add) with the latest "official" snapshot and a snapshot with USB3 disables using the patch.
The only difference i noticed was that usb3 was disabled :). That and the fact that when i plugged a usb3 harddrive the router died the first time and then i saw weird errors:
[ 93.472005] usb 2-1: new SuperSpeed USB device number 2 using xhci-mtk [ 93.506434] scsi host0: uas [ 93.510324] xhci-mtk 1e1c0000.xhci: ERROR Transfer event for unknown stream ring slot 1 ep 4 [ 93.518763] xhci-mtk 1e1c0000.xhci: @000000000f7ca170 0dc18000 00000000 05000000 01058001 [ 93.526908] xhci-mtk 1e1c0000.xhci: ERROR Transfer event for unknown stream ring slot 1 ep 6 [ 93.535314] xhci-mtk 1e1c0000.xhci: @000000000f7ca180 0dc18100 00000000 05000000 01078001 [ 114.461636] scsi 0:0:0:0: tag#0 uas_eh_abort_handler 0 uas-tag 1 inflight: CMD IN [ 114.469204] scsi 0:0:0:0: tag#0 CDB: opcode=0x12 12 00 00 00 24 00 [ 114.475520] xhci-mtk 1e1c0000.xhci: Mismatch between completed Set TR Deq Ptr command & xHCI internal state. [ 114.485307] xhci-mtk 1e1c0000.xhci: ep deq seg = 8dc01200, deq ptr = aead8010 [ 115.551601] scsi host0: uas_eh_device_reset_handler FAILED to get lock err -16
Mind you this is from the stock snapshot.
With the patch that disables USB3 the drive connects properly:
[ 762.864874] usb 1-1: new high-speed USB device number 4 using xhci-mtk [ 763.058565] scsi host0: uas [ 763.062822] scsi 0:0:0:0: Direct-Access Seagate Expansion 0708 PQ: 0 ANSI: 6 [ 764.866108] sd 0:0:0:0: [sda] 1953525167 512-byte logical blocks: (1.00 TB/932 GiB) [ 764.873767] sd 0:0:0:0: [sda] 4096-byte physical blocks [ 764.879344] sd 0:0:0:0: [sda] Write Protect is off [ 764.884133] sd 0:0:0:0: [sda] Mode Sense: 53 00 00 08 [ 764.884573] sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA [ 764.991112] sda: sda1 sda2 sda3 sda4 [ 764.998675] sd 0:0:0:0: [sda] Attached SCSI disk
But at usb2 speeds as expected.
TLDR: Just flash the latest snapshot.