The SX has a cuddy, the LX has the open bow. The SX's have big block power options, (small block standard) the LX are only small blocks. (The 6.2 is supposed to be a 'big block replacement', but cubic inches don't lie)
Mine has a Mercruiser 320hp 6.2L w/Bravo I, largest engine offered then for the LX. All the new Stingrays are Volvo Penta, so 350 320hp is the largest. It hits an honest 60+mph with a couple in the boat. Mine has the Captains Call exhaust, switch on the helm that goes from thru hull to thru prop instantly, (it's always on thru-hull

) it's not as loud as my Sunbird, but it sounds very, very good. Plus it is like new, (72hrs) no wrench turning... yet. I bought this boat without ever having ridden in one, let alone even SEEN one in person! I knew it had the power I wanted, had to have the open bow, and I really love the lines of the 230's, long and sleek, very nice size for a microboat.
Speaking of Sunbird, here is my 1986 Sunbird GT208. 300hp 350 OMC Cobra, 4" Through Hull via Revolution Marine exhaust manifolds and Hardin Marine 4" Tips that exit at either side of the transom under the swim platform out of the back, very unique setup. I love the boat, but it has some transom rot, I decided not to fix it so am parting it out. Everything for sale.