I noticed besides some styling cues, the two are about 1000 lbs. in weight. What are the other differences? Thanks.

Twin step hull on the Lightning vs single step on the Ex. The Lightning is several mph faster with same power. Cockpit is a little nicer on the Lightning and the cabin is a little taller.

The X has 496 vrs 525's for lightning nicer interior&hull is faster

Usually but not always. There is one Ex for sale with 525s and I've seen a few with 500 efi's. There are several Lightnings with 496 HO's, a couple that are owned by board members.

If you are over 6' tall you won't like the seat position of the Ex. It is real close to the dash. I don't know if it is diff in '05 but it was a lot closer on an '03 I looked at vs. my lightning. That was the deciding factor for me.