London vs Singapore

Couldn't find any recent threads on this, but apologies if it's been asked before.

For someone just starting out a career in IB, how do London and Singapore compare? Thinking mostly in terms of career progression, exit opps, exposure, deal flow etc, but would also be interested in pay/culture/whatever if they're significantly different. Mostly looking at BB comparisons (e.g. MS London compared to MS Singapore) rather than local banks.

Also, how easy is it to move between the two? I've read that it's easier to do London -> Singapore rather than Singapore -> London, but I'm not sure how true this is. Would it be feasible to start off in Singapore and then move back to London as an associate, or by this point are you confined to Asia?

For someone who's not 100% sure where they want to be, which would be the better choice?