I'm kinda with these last guys - I stayed a month, thought it was pretty overrated on the whole but I'd say I've been spoilt. I don't want to be a downer so it has some positives tho:
generally cheap
Food - generally great
cheap & cold beer
kite boys / compressed air on the beach
can't beat beach bars, spring rolls & beer while you're still dripping
scooters are fun
great kite culture, everyone on the same buzz - great to chill at beach bar and watch the show on the water
cheap/free wifi everywhere
Negs - can be managed or ignored mostly:
water - not the cleanest, like qld bay water
beach- clean where they sweep every morn, lots of rubbish elsewhere. I almost stepped on a used syringe off a fishing boat on the northern beach
beach - narrow at high tide, launch over buildings almost or between tables/chairs, depending on where you are on the strip
learners in bad conditions - they were strapping total beginners in lifejackets and sending them out down the beach in 25kts and 1m swell, sending a rescue boat once they're disappearing over the horizon. You'd never send out someone here in those conditions.
shops - pretty limited in vietnam vs other SE asia, post commie they have the same rubbish in every shop, you can see they just go - lets have 5xtourist shop here and so they build/stock each exactly the same, down to the same stuff on the same shelf in each..
Also pick your spot some places had *loud* clubs, good if you want that, terrible if you don't. Other spots quiet & nice.