No...I'm not dead. I've been in London for the last fifteen days seeing 13 plays:
1)Derek Jacobi's LEAR
2) Sir Peter Hall's TWELFTH NIGHT at the NT
3) Sir Peter Hall's THE RIVALS
4) THE WAR HORSE (again...when I saw it in 09)
5) NT's GREENLAND
6) Sir Richard Eyre's FLEA IN HER EAR at the Old Vic
7) VERNON GOD LITTLE at the Young Vic

West End transfer of The Royal Court's CLYBOURNE PARK
9) NT's SEASON'S GREETINGS w/Catherine Tate
10) a rediscovered Terence Rattigan play, LESS THAN KIND
11) NT's FRANKENSTEIN directed by Danny Boyle with Benedict Cumberbatch.
12) THE HERETIC at The Royal Court
13) J.B. Priestly's WHEN WE ARE MARRIED
All were well worth seeing, many were great, all the rest good.
As for SPIDERMAN the musical. Sorry, even if you call it a preview, once you start charging full price, you've opened and are fair game for the critics.