Which gen v12? I have paddled gen 1 and 2 extensively and had an SEA for a month but only used on flat water.
Both brands are excellent build quality. Compared to the 2 early generation epics the SEA felt like it had less primary stability. It for me (165lbs) had a a noticeable wobble in little 10-15 cm waves even compared to the v12 g1 which was known for loose primary and solid secondary. I would be curious if others found that or it was just me.
I never paddled the SEA downwind. Saw a friend do it and it looked like it carves well. I am a big fan of tail rocker and low volume tails (See my gushing review of the Vega downwind).
Remount on the SEA is not something you want to do often. Rails sharp like a knife!
Bucket comfort was fine on the SEA. Better for me than G2 but worse than G1 epic. All butts are different. Fortunately the SEA cockpit is not the porcelain bathtub of old. I wish I knew how the v12 G3 bucket fits me so I would know if I should order one!
Current Skis: Nelo Vanquish AIR, Epic V10g4, NK 670 double, NK exrcize, Carbonology Feather, Think Jet, Knysna Sonic X
Former Skis: Epic v10g3, Kai Waa Vega, Epic V12 g2, Epic V12 g1, Epic v10 double, Nelo 550 g2, Fenn Elite S, Custom Kayaks Synergy