I have one of the new Airflo Long Deltas, you are right, there is is no splice. While I briefly cast the Delta yesterday I can speak more about the Long Delta as I have had it for a couple of months.
While I am not a devotee of shorter speylines, I am not against them either. I see a niche for this "mid-spey type" line in my fishing - especially on some of those nasty Thompson afternoons when the the wind quarters upstrean at you. The Airflo is amazingly slick and it seems to me has a very slim profile - really cuts the wind, yet unlike the other line that incorporates this characteristic in its name - I find it pleasant to cast.