The tittle of this thread mentions 100-seats not a MD-88 replacement. IMHO, DAL needs a DC9-30 replacement more than a DC9-40/50/88 replacement right now. A 100 seater would work wonders in those former Heartland markets like GFK and FAR which now see a mix of CR2s, CR7s, CR9s, E70s, E75s, 32Ss and M88s. A true 100-seater like the CS-100, a 98-seater like the ARJ21-900 or a 106-seater like the B717 would right size some markets offer a more homogeneous gauge of equipment and reclaim scope where the M88 and 32S might be too big.