I just got an offer, and would like some advice from you :)

Recruiter reached out around Christmas time for IC role (E6), and recently i got offer confirmed (no offer details yet) as L5 "Software Engineer (Tech Lead)".
YOE: >15, have been in management/leader roles for the last few years

My questions:

• are L5/E5 and SWE/IC/Tech lead the same thing?
• what kind of package should I expect/negotiate?

Seems like there are not much info on the web with my YOE, esp. for London.

My gut feeling is this won't be an ideal move when I think of quality of life (I'm in EU atm); Although FB could potentially offer a bit more money and better exposure.

Thanks!