Given that all these ISPs are essentially reselling the same Openreach infrastructure, using the same phone cable with the same GEA-FTTC wholesale costs, then product variation is very different. Yes, they might have slightly different internal or back-haul costs, but product differentiation at the basic service level is always going to be difficult.
That's why, in that you see differences, these are often at the level of what's bundled. TV/sports/film channels, special short term deals and so on.
For their to be fundamental competition, it would have to be at the infrastructure level and, apart from VM and a few small Altnets, there's not much of that about. The issue is the cost barrier. Putting MSANs into exchanges is one thing. Putting in any form of large scale network infrastructure over large geographical areas is something else again.
nb. contention is a potential issue as that is under the control of the SPs. Personally I've never seen any contention on my FTTC service in that speed test results are within 10% of one another whatever the time of day. Other ISPs (or locations) may vary.
Edited by TheEulerID (Mon 10-Nov-14 13:47:59)