The differences are... (I'll contrast to the 14" limited edition 299A, since it is most comparable to the new X5).
1) The table is larger than the 14" Ltd ed by 2" in both directions (like their older models).
2) The spring handles (wrench-like handles) for making trunnion tilt adjustments, instead of star knobs. I see no big advantage here (easier on hands when cinching down the adjustment?)
3) Hole cut in bottom of casting and door which falls into a diagnonal chute, which goes to a 4" dust port in back of the base... Is this better or worse than the old one?
4) Quick tension release.
Whats the same ? Same 3450 RPM 1.5 HP motor (its the same motor used in their contractor saw). Same rigid rail mounting system in the base, except base has only one door on right instead of 1 on both sides...
I could probably get the bigger table to put on mine (its the same basic tool), and then I believe it would be better than the X5. I prefer the dust collection in front by the blade. I have a modified Delta dust hookup made for the 4" hose. I think it works pretty well. I also think for this tool you NEED the link belt. My belt looked great but it had a set in it and made the tool actually sway when it ran. The link belt eliminated all movement.