Bob,
I really doubt the Slate blue Performer is made any differently or in a different factory than the Crimson, Green or other colored kettles. So in terms of durability, I wouldn't worry about that.
I love the color. If you do to, then buy yourself one.
The newer gen models do sit a little higher and that is nice. I have owned all of the gens and prefer the older SS table Performers, but I did install 13" wheels on mine to lift it up. I'm also 6'2" and the original height of the SSP are way too low.
The new ash pan might be more difficult for you to use. I like the older turn style ones. Good news is, if you buy the new Performer and end up not liking the new squeeze style, then you can just swap over the older style from your deep blue grill.
Have you tried taking a bottle brush and sticking it down the burner tube on your old Performer? It's likely that your igniter still works, might just be dusty of have some ashes or cobwebs down there. Just remove the fitting that holds on the propane black tubing to your burner tube....flat head prys it off....then stick bottle brush down there, blow out with some air and you should be ready to go.
The center piece on the GBS grate won't fall off when you lift it up if you fold the top flap down. The folded flap keeps in place.
Post some picture when you get the new one!