We've been up on the new VPS at gridvirt.com for a week or so, and I'm quite happy with the performance so far. Page response time has sped up noticeably, and the servers seem to have no trouble keeping up with the occasional traffic spikes. Here's what google's webmaster tools is telling me about average page download time:
Lower is better, and you can see how the performance was progressively getting worse on our old host. Switching to Ramnode (which was fast, but spotty), and now Gridvirt (which seems fast and reliable), shows up clearly on the graph.