Personally i'd compare the midline woofer to be competitive with the SX series from RE. Except it is using a regular round wire coil is standard on the midline - with the option to do the flat wind aluminum for like 20 bucks extra. Obviously not the same woofer, but as far as preformance goes i'd match those two up just to give you a realitive idea on potential that it has. (10's through 18's will be built) 3" coil etc.
The entry level sub in this case is between the RE and the SE (16mm of x-max) works well for ported or sealed. Just to keep the example the same would be competitive with the SE series from RE. Based soley on a comparison of preformance basis, nothing else other then that. Say 300 watts rms on this series.