Well, the upfront cost of beckett style skimmers is lower, but over time, the operating costs can far outweigh the upfront cost. I used a pan world 200ps on my dual beckett from MRC, and it was an excellent skimmer, pulled out lots of nasty gunk! BUT...it draws close to 300 watts! With rising electricity costs, especially here in the northeast, or even worse out in CA, it works out to be a much better deal to put the extra money into a high end needlewheel skimmer. Personally, I am saving about $350 per year with my Deltec 851 vs. the MRC skimmer.
There is also a noise factor, and potentially a microbubble factor is your system isn't set up well to handle a influx of bubbly water from a beckett.