Are you looking at a zle for track work or just street driving / fun use? I swapped from a z/28 to a ZLE and am very happy I made the change but I'm heavily track focused. The z/28 has a theater and a presence that just cant be replicated by the zle however the zle is a much better car; interior, handling, creature comforts etc.
If street driving; keep the z/28 (it's fairly softer then the zle as well); if track day driving then you'll find lots of rewards in your change but should still weigh the economic impacts.
Here's a review I wrote about the two cars in a track setting. Might be helpful:
https://www.camaro6.com/forums/showthread.php?t=550165