You guys don't know what you're talking about: a lot of people here had HUGE problems with Amtrak back when OcUK were using them. I've had two large deliveries botched up by them (and both times I was lied to with the old "we couldn't find the address" excuse when I live on a main road). On the first occasion they didn't deliver for three consecutive days on which they said they would, and threatened me on the phone that they would send their drivers round when I expressed dismay at their increasingly more and more ridiculous excuses (not that their threat scared me as they probably wouldn't be able to find the place) and in the end I had to go pick it up myself from their depot; on the other they held my goods for 9 days without notifying either me or the sender that they couldn't deliver (even though they had my mobile number and lied that they tried to call me, unaware that Orange send me missed call notification texts whenever someone tries to call me when my phone's off).
Admittedly a lot of the Amtrak problems were being reported by the same people so maybe it was particular depots that were being staffed by apes. CityLink, however, I've been using for years when ordering from other etailers and I've never had a problem, and I think the fact that even OcUK switched to them testifies that, overall, they're much more reliable.
One thing I should note, though, is that OcUK's delivery charges are slightly higher than those of other etailer's using CityLink, especially for small orders.