To be fair, the GLS is a lot smaller and lighter compared to the Telluride.
Something like the GLS (non-performance variant) handles more like the Telluride than the GLK (and now GLC).
The upcoming Genesis GV70 and even the performance variant of the new Tucson will handle more like the small Mercedes CUV.
Mercedes is very good at pushing the tech boundaries, but will be paying $$$ for it.
The new Tucson will be filled with just about all the tech one would really want or need without going overboard like the the new S Class.
Biggest difference between the Telluride and new GLE is more interior room/usable 3rd row) in the Kia, but more power and a nicer interior in the GLE (the interior in the SX-P is premium, but not quite "luxury").
Have to weigh which things are more important for your own needs.
While subjective (to a point), the Telluride looks better.
If decide that more power and lux are higher up on your list, another option Wil be the Genesis
GV80 which will be hitting the dealer lots sometime in October.
MSRP undercuts the GLE, but initial demand may see it go for above list (like for the SXP) while discounts can be had on the GLE, so the price gap may not end up being as big.