Yes, Bangkok has a lot of noisy traffic compared to the shires back home. But if you are from London, it's not as bad as London. Here the roads are long and straight. So the traffic moves faster than in London. Also, crazy Thai drivers and bikers helps keep traffic moving

But then, most places that you would want to go to can be reached by the underground or by the Sky train (overland trains) or by river buses. If we are just talking about punting, Nana Plaza, Sukhumvit 11 and Soi Cowboy are all in the same walkable area.
If you want to visit Bangkok, don't let the traffic stories put you off.
Pattaya is convenient to get to from Bangkok. But, apart from punting, there isnt much else there. The place is full of old white guys walking around with young Thai girls . Then there are the bars, massage parlours. And that is about. If you are hoping for a bit of civvy action, forget it. Phuket is the place for that. Mainly because Phuket has other things to do apart from punting and the beaches are a lot better.
Phuket appear to be full of Russian guys with hot Russian GFs. And parties of young Western backpackers. A very different vibe compared to Pattaya