I'm new to DH, having signed up only a few weeks ago and smack-bang in the middle of the performance issues.
For a few days, I feared that I'd made a huge mistake. I'd signed up with DH following recommendation, and had heard so much of them over the years that I didn't stop to review their current performance. For a few days I had spotty connections, poor loading and generally a poor service and was cursing myself for being such foolish and rushing into the change.
Since DH finished the upgrades, everything's been running as clockwork. It's taken me a few days to become accustomed to the panel following several years of cP, but the Wiki is detailed and where that failed me, support tickets have been friendly, helpful and fast.
I'm still within my trial period, but if the performance problems have indeed been rectified - and it seems that way, at least on my server - I hope to be very happy here.