I saw The Seafarer at the Booth multiple times -- once from the balcony, twice from rows D or E, and the rest from BB (the 2nd row)
Seafarer was a fairly intimate show, and I would imagine Thurgood must be even more so
I also saw Faith Healer there a few years ago (another show where only one person was on the stage at at time) -- from the balcony
For both Seafarer and Faith Healer the balcony was WAY too far away, for my taste anyway
So I would say 'the closer the better'
The 2nd row was PERFECT -- you could see everyone's expressions and you caught so many more little gestures
I would say Center Orchestra, and as close as possible
You don't go to the dragon without a present - Mark Rylance