The lack of midstroke support is balls, you’ll have more for a given amount of sag – but you’ll have less bottom out resistance.
Incidently, properly shimmed shocks like Vivids, DVO’s, Mazocchis, BOS or Ohlins can be tuned to have progressie shimstacks and be fitted with heavy bottom out bumpers which negate the need for a progressive spring rate. The X2’s can’t be given progressive shimstack tunes (unless modded by avalanche…possibly) because they rely on bleed valves to regulate oil flow. Some shocks, like the Eleven Six, RC4, DHX5 can have the pressure in the piggback altered as well – which alters bottom out resistance. Reviews on the eleven six seem to indicate that it feels just as playful as an airshock.
You can also run less sag and still end up with similar grip that you get with an air shock, due to the more sensitive nature of the coil.