Sounds fairly normal.
The loud exhaust is probably 'cos it's been a replacement non-OEM rear box (at least).
The acceleration - if gentle in normal 'economy' mode - it'll just carry on in 3rd/4th, but if as you say you kick down - it will drop to 2nd...and sometimes 1st.
'S' Sports mode will set the kick down a bit more aggresive & get it revving up to the limiter if you keep your foot planted. 120 ish is not uncommon in 3rd
As for being quicker - I think the GLS weighs a wee bit less than some of the others, and that loud exhaust will be adding to the 'sensation'!
Traffic Master - disconnected mine, but a new subscription isn't all that expensive. Suppose it's a good idea if you do a lot of deadline motorway/main route miles.
Well, that's my take on it!