I've driven (on canyon and track) mostly stock: 718 Cayman S, GTS 2.5L, GTS 4.0L, GT4, and Spyder.
Comparing 718 Turbos.... not as exciting as Emira AMG i4 at all (and both have piped in sounds) but PDK is unmistakably superior to AMG DCT.
You need chassis upgrades to non GT 718's to match Emira's stock bits (for track).
Also no surprise, steering is better (just slighly) on Emira, and becomes noticeably better as you get more aggressive.
Note on GTS 4.0L vs GT4/Spyder: Engine and gearing is almost indistinguishable, and very similar on canyons.
On the track however when driving at 10/10, the stock "GT upgrades" differences become very apparent.
Speaking for the street/canyon driving... the NA 4.0L engine reving to 8k is just... so much more emotion as it just builds and pulls and pulls. Emotion is amplified with the top down on the Spyder (or GTS Boxster).
Emira V6 you get to have some fun rowing through the gears, but it's a different "emotion" than the 4.0L. I'd say it's the analog feel and makes you feel like you're actually working with the car as opposed to being taken for a ride.
The 4.0L feels like a muscle car in comparison to the V6.
Imo, a fairer comparison would have been if 718 GTS 2.5L engine in a GT4 body would = Emira i4.
GTS 4.0L with GT4 upgrades would = Emira V6.
Emira just has a better stock setup for "aggressive driving" than the 718 turbo and non-GT variants (but I must put a disclaimer: better does not mean more reliable

).
Creature comfort wise, GT4/Spyder is lacking compared to what the non-GT variants has.
Plus the interior is from 2016... literally quite dated, but still has its appeal for its simplicity.
The 18-ways sofas > Emira seats though.
That being said, I have both a Spyder and a v6 Emira in my garage. I have a ton of fun in the Emira (when it's problem free). Just with the decat it makes the sound on pulls almost as exciting as the 4.0L howl (with over-axle pipes).
The post is already long enough and I have way more opinions on the Emira, but at the end of the day for me: Spyder is a forever car, Emira is gone after warranty runs out. It'd be a tougher choice vs GT4 but the Spyder is just that much more special
P.S. I'm unreasonly annoyed at the incorrectly Ai-generated front end of the Spyder in the OP. It has the base 718 nose in the last two pictures. Emira is no doubt prettier and a head turner. The Spyder is a future classic with them humps.