When I suggested, back in 2007, the second TT in June, I thought of the sporting course for, I suppose, selfish reasons: 1) I find Sunday 6 AM starts horrible - Saturday afternoon is more civilised; 2) I would rather do a shorter, technical course than some monotonous DC 50 (which is the only other event that weekend as I rememeber).
Also I was looking to the future a bit: DC courses are more likely to be lost due to increasing (not sure for how longer though with petrol going up again) traffic counts and for this reason over recent years I believe there's been a trend towards sporting courses, not just in the early season.
Having said all that there does seem to be this fixation with regular distance DC courses among the TT community as a whole.
The numbers for the two June TT's we've had have been disappointing, but interestingly the field has each time been high quality.
I think if we could get 40 entries for the June event (maybe by bolstering with RCC entries) we could consider it a success. If we thought we'd only ever be getting in the 20's, I'm not sure it's worth it.