I'm noodling over some options I have on an award redemption for returning home from a holiday and figured I'd ask some fellow FTers.

Option 1:
LHR-ORD(12 hour overnight)-SEA on the A380, BA F + AS (Alaska Airlines) F

Upsides:
The A380 is nice as you'll get, T5 experience, can use public transport to get home from the airport when I get home. Guaranteed F on the connecting flight (Alaska domestic F ~= AA domestic F not on the transcon routes, near enough.)

Downsides:
Staying overnight (I'm blowing Hyatt points on a redemption for the Hyatt Regency ORD at the moment as a placeholder, otherwise it would be $80-100ish for an ORD-area hotel). Longer AS flight (not that an F seat is bad, just still, 4 hours vs. 2).

Option 2:
LHR-LAS(3.5 hour connection, the PP lounge at LAS might be my hangout, though I don't have PP yet)-SEA, BAF + AS Y (but an excellent chance to get the upgrade to F). If I really wanted to I could overnight in a suite near LAS for about the same (and guarantee an F seat, call this option 2a, though it has most of the downsides of Options 1 and 2 and not as many of the upsides, so I'm sort of "meh" on that, leaning no).

Upsides:

Get all the flying done in one go. Sleep in my own bed at the end of the very long day. The connecting flight (LAS-SEA) is shorter. No need to do an overnight stay at a hotel. Not having to deal with ORD (not a fun airport).

Downsides:
T3 instead of T5 (though the T3 lounges aren't too shabby). By the time I get in, I'm paying for an Uber/Lyft to get home. Pay for lounge at LAS + Uber = a hotel room at ORD or LAS (and 3.5 hours is barely enough time to leave an airport and come back, so probably not going to do that- if I wanted to visit Vegas I'd do the overnight). A380 > Mid-J 744 by quite a bit (no WiFi, 744 IFE has good chance of being dodgy and not updated, cabin is smaller, A380 is just kind of nicer overall). Not 100% guaranteed to get upgrade on AS (though I've done SO many Y flights SEA-LAS-SEA it's not a huge deal, and the odds of an upgrade are very good).

So what would you do? They are both daytime/evening flights and I'm going to be trying hard to adjust my body to West Coast time, so no real sleeping on the plane (at most a short 30-60 minute nap, but not if I can avoid it), so on plane experience is important.