The XL can come in a 68" length, which the XL-#D does not. The XL-3D comes in higher poundages. The limbs are different too. The XL-3D has double laminated limbs, while the XL is single. Offhand, I think the higher poundage and upgraded limbs means the XL-3D has an 'eye' for speed, probably why the 3D is tacked on there. The regular XL is probably geared more for shooting fixed distance where speed is not quite as important. Unless you want a bow lighter than 40# or longer than 66", I would go with the XL-3D. They are about the same price, the XL-3D has a detailed review online with speed figures, and I have a feeling many here would testify to its shootability and speed. I have two warf bows with carbon limbs (sky conquest and samick), a martin hunter, and a mahaska recurve, in addition to the XL-3D. I have not chronographed any of these, but my judgement based upon shifts in arrow point of impact and watching the arrow fly is that the XL-3D is the fastest of these bows (for the same draw weight). With the 66" length, it is also very smooth and fun to shoot. Hope this helps. I stripped the paint off the riser and painted it a flat gray with aluma-hyde II (a 1 part gun coating from brownell's) and duracoat'd the limbs. It looks like a slightly long, proper hunting recurve.