Why buy a broadband router off-the-shelf?

Not sure about this “which” research conclusion.
I can only speak from experience. I’m with TalkTalk and I went through three wireless routers in as many years. I got to the stage where I bought a better quality wireless router off ebay at a budget price (£10) and I keep the TalkTalk offering as a reserve. So far the cheapo ebay unit which is also of a higher technical spec’ has lasted better than any of the TalkTalk units, the latest of which is now sat on the reserves bench.
This approach works better for me because it’s such a hassel getting a new router out of TalkTalk when their low quality unit goes pop each time.
Perhaps customers of other ISP’s do better?
Don’t know.

I switched my BE supplied wireless router (a SpeedTouch) for a Linksys WAG160n. A lesson learnt from both routers is the need to ensure that you have the latest firmware installed.

The Linksys raised my Internet speed from approximately 8 MBp/s to over 10 MBp/s and the wireless-N enables me to get a full 55 dBm signal in my garden office compared to 65-70 dBm

Although I note that a number of ISPs do provide better routers these days, I still recommend getting a good mid-range router.

We have a house with very thick walls through which WiFi doesn’t travel well so we use several Apple Airport routers which create one seamless network throughout the house.

I bought my Belkin router new on eBay for £13 and have never had any problems with it.

Many of the ISP supplied router/modems are just re-badged Netgear, Dlink etc versions with different firmware which can make it difficult to use with other ISPs.

ISP supplied ones are often going to be easier to set up as they are often pre-configured with username, password and wifi passphrases, I dont think this makes them inherently easier to use though ?

I struggled fro months after my BT-supplied Voyager 2091 router failed and I installed a Home Hub 2 that BT had provided. Drop-out was dreadful. I called BT and an engineer eventually came out and spent a long time not solving the issue, despite changing the Home Hub 2 for a new one in his van. I’d thought the wirelss coverage would have been better with later model routers. Wrong! I bought a Netgear Extender in the beleief that I would add range to the wireless signal from the HH2. Right! And wrong! WHen it connected with the router, it gave a strong signal. Problem was that the router was so poor that the Netgear extender frequently lost the poor wireless signal from the HH2. By this time, I’m getting bad earache from wife and daughter who also couldn’t hold a decent wireless connection, although the HH2 is still internet-connected (lights are all blue). I finally decided that I’d speculatively try a Belkin Play DB600N+ modem/router. Problem solved instantly. Dispensed with HH2 AND Netgear Extender (now redundant) because I have a wireless signal direct from the Belkin everywhere in the house! I’ve used the Belkin for fully a year now and I can’t remember having lost a wireless connection even once in all that time. You’ll NEVER convince me in a month of Sundays that independent suppliers’ devices are no better than ISP-supplied equipment!
Despite having been courted on numerous occasions by BT to upgrade to Infinity since the local exchange went fibre optic, I’ve resisted doing so because I don’t trust BT’s Home Hubs any more. I still read in forums about wireless connection issues with HH3s. So, at the end of this month, when my renewal falls due, I expect to be going elsewhere.