Warbirds of Prey servers are indeed a well managed set of servers. They offer high quality objective based missions on high performance hardware. For a guy who lives in Scandinavia, I have rarely problems with lagging or high ping, and when I do it is exclusively because of my own shortcomings hardware-wise.
If you have issues with any mission, please let them know in their forum - they have always been open for suggestions regarding improvements... both the "Old" and the "New" management.
I have no complaints at all - other than rare occasional bad bahaviour amongst ceratain pilots, and that is not their responibility - but they do "police" the activity on the servers.. VERY closely and eagerly
.. bad behaviour is found on any server..
I highly recommend Warbirds of prey servers - pretty much the only ones I find to meet my demands on quality "air time"