I'll just tell you what electros I've had for awhile and like
A1 Fly (mine has a tadao) - What I use the most.
Karnivor (with tadao board if you wanted it tourney ready)
G7 (mine has a virtue so tourney ready)
SR with MQ2
Lasoya Promaster (has a mostly tourney ready board)
All of these have worked great in the cold. Angel G7/A1 Fly maintenance is dead easy. Much like autocockers it's a couple drops of oil every couple cases and lube the reg (+ram for angels) now and then.
The only one that's been finicky is the SR with MQ2 (the mq2 specifically). The A1 Fly and G7 come with great triggers. My Karnivor and Promaster have been upgraded to have a nice triggers with bearings.
While I have little experience with spool valves. My experience with poppets has been they're very easy to tech.
Since I'm a gun whore I'll be getting a marq and a shocker nxt to try