When I first started cycling, the two main online retailers I used repeatedly were CRC and Wiggle. One or the other always had the best prices around on the web. Heck, for a while I was buying so much I maintained a Wiggle Platinum membership for over 3 years!! However, these days I find myself mostly ordering from other online UK bike shops /suppliers as they tend to be cheaper (and the postage is much faster too).
Wiggle really went down in my estimation when they started charging a premium to get your order picked up and dealt with quicker. After that, I'd regularly see my non-premium orders (which would previously have been dealt with in 24 hrs) creeping up to around 4 days before they'd be picked up & processed. CRC always seem to be out of stock of anything I'm looking for these days - stock control seems to have taken a back seat there in the last few years.
Maybe together they'll be better - but they're going to have to go some to get my regular custom again.