All those vacuums are over a decade old, so you're going with a decade of use, so purchase wisely so you don't get a lemon. The XL Plus if it's the old squarebody one, that came out in 1999 I think? The XL2 came out sometime in the mid 2000's I think.
But kirbyvertibles are right, both Orecks are similar in constriction under the hood, they just made the design more streamlined to keep up with other vac brands.
I'd go with the more recent Oreck if you had to choose. The Riccar will be above both of them performance wise though.
I've had some bad experiences with the old Y2K era Orecks, both thrift store finds, their motors are nearly dead and need a good TLC and some maintenance. Most of the noise sounds like vibration clatter so it might not be as bad as I fear. But I paid around $13 each for them so I don't mind some repair specials.
My grandmother loved her Orecks, and they seemed to do a good job on her double wide mobile home. My local Salvation Army also employed a Oreck XL to clean the store entrance for some 5 or 6 years until I guess it died of retail lint suffocation.
