I use a Garmin Dezl 770 around London (Mount Pleasant region and South) and gets me around fine. It seems to generally find slightly faster routes compared to the TomTom equivalent when compared to other drivers doing the same routes at the same times - At times you do need to check the routing as it might get a bit creative and suggest using wider “Main Roads” compared to smaller minor roads that you can get a 7.5 Ton down…The traffic info is great too
Totally worth the price in my opinion