PL lettering is in the official Premier League font (as one might imagine) while Spurs lettering is in the 'Tottenham' font that we use in Europe. Both look decent but some names do look particularly swish in the Spurs lettering (in my opinion).
Below are photos for comparison.
Premier League lettering:
Champions League:
The slightly annoying thing is that Spurs never seem to let fans buy the
away Spurs lettering, meaning you can opt for CL badges on the away shirt but won't be able to get a 'proper' recreation of that kit, i.e. white lettering like this...
I quite like it, depending on the name/number in question. While I understand the branding that Spurs are trying to establish with that licensed font, I'm quite partial to the geometric lettering (with a straight horizontal name) that some other clubs use in Europe, for example United...
We dabbled slightly with that a couple of years ago...