They're a bunch of cowboys. Expect ever increasing delivery times as they slowly work out they don't have the network capacity to provide what they've sold you, hopeless account managers and illogical provisioning in the extreme. Some engineers are OK, some are complete idiots. Then you have the issue the CPE is cheap and prone to failure...
But they are very cheap.
It's a trade off, if you want a 10-100Mbit circuit for as little as possible and you're prepared to hassle their project managers three times a week until it gets installed then maybe it's worth it.
There's also the aspect there's not a whole lot of decent providers with real nationwide coverage that I've got anything good to say about. Colt are the stand out decent ones to deal with for remote office circuits, fibrenet used to be good but got bought by global crossing and are now spectacularly bad.
In comparison to most, BT WES services are excellent (but I've only one experience of their internet access product and it isn't good - it's being ripped out despite having a year left on the contract it's so bad in fact.).
