The XLT was originally known as the Extra Lite Triple(XLT). The XCR was more of the perfomance sled also with the triple and a little bigger carbs. The 97 - 98 600 XCR was Case Reed intake, 3-VM38AL carbs and a tuned triple pipe (600cc)and 550 lbs. The XLT Special was Piston Port intake with 3-VM38SS carbs with a tuned pipe exhaust (597cc) but only weighed 505 lbs. Over the years the XLT had the better suspension travel by almost 3". XCR was the quicker sled, but the XLT out sold it at least 3-1 and was the better value. OB
I had a 97' XLT Special. Friend of mine had a 00' xcr. We ran them several times. Both stock, studded tracks and full gas tanks. We drove each others sled too and even had a 3rd rider run both. Our conclusion was what ever sled the rider that weighed 40lbs less than the other two won by 1/2 to 2 lengths with a slight edge to the XCR. The XCR ate up a whole lot more fuel though.