I could ask the question: How many points did you get for the 2.5 hour UD job versus the much longer BOINC job and how much does that equate back to points per hour? Check the Result Status page for the detail awards. (BOINC credits convert to WCG points by factor 7)

Actually, there's a lot more work packed into the BOINC version, who are in fact faster as there is no continuous encryption overhead like the UD agent has. WCG techs are trying to squeeze an amount of work into a Task that lasts about 6 hours on a reference machine. Because the calculations are non-deterministic, they actually last e.g. on my C2D from between 4.5 to 6-7 hours each.

Added: Result Status page link

AFAIK there is no mail if you migrate to BOINC from UD. All members have a BOINC Hosts and Cross-Project ID assigned which you can see in the My Grid > My Profile page. Also whether you run at 100% or any lower percentage, the BOINC client only reports actual CPU time used, where the UD client reported wall-clock time.