Good if filterless, but the concept constrains filter size, and cone filters are small on pleat area anyway. The result is filter loss.
Built this one early on. At 390 air volume, pressure drop was poor. Looked at larger cone filters, then rejected the whole concept.
Only the flat filters have pleats 7/8" to 1" deep. If cut from the frame and spread out, the media area is huge. The goal was to see how large a flat filter I could stuff in the available space. This is a K&N 33-2124.
Measured filter loss was less than the filterless drop published for a Bower intake, and it's always filtered....no worries.
I have the SJ MK-3 FAB with the K&N E-0995 cone filter. This filter flange gets cut down to limit the diameter. The alt air flow path is not as clean as Dans, and the filter diameter is a challenge for clearance, even with the SJ cowl. At 3G's the air box touches my cowl.