DT is the best off the shelf system out there, all networks,those on DT and those on home grown systems all experience the same problems. People get frustrated with DT because they need someone to blame. A lot of times its user error on the network side that makes DT look bad, but sometimes its how the system is designed as well.
We have had minor issues on DT but nothing that you don't expect or plan for. The problem is people forget how much traffic DT handles on a day to day level (
directtrack.com - Web Site Audience Profiles from Quantcast this is just the networks on the shared option, most of the larger networks are on their own servers which are not counted in these traffic stats, with some bigger networks
Quantcast Traffic Comparison for copeac.com + directtrack.com + tracking101.com + clickbooth.com + ).com. At the highest points with this small example you'll notice that DT handles 2.5 Million users a day, i would estimate that with their entire network they see traffic of 3-9 million users a day across all the networks on their platform. You really need to take that in to consideration when reading about peoples issues with DT
If you're going to move on to the Dt platform i would suggest that you get a dedicated option as opposed to the shared application. It costs more but is much more stable from our experience. Those traffic spikes on DT are so large they do cause a slow down if youre on the shared pool