We have spent a few days in the marina during the last two years.
The marina is very comfortable. boats are moored at short finger pontoons mostly and the staff help you to moor up. There are several sets of showers and toilets which are of a very high standard. The office is fairly efficient, and there is a chandlery and a laundry which was cheap and very efficient - it is almost industrial in its scale as it processes bulk laundry for flotillas. There is also a swimming pool. Security into the site is tight and you go outside the secure area to get to the cafes and bars and posh clothes shops that people seem to think go in tandem with marinas. There can be quite a lot of noise from these bars and discos at night.
The town at first sight seems rather a mess of broken pavements and down at heel buildings. But as you explore you find a large Migros supermarket in the centre, a very big covered market, and plenty of other services such as mobile phone shops, restaurants and more supermarkets (Tansas).
There is a dolmus station behind Migros from where you can get a bus to most places on the Bodrum peninsula and of course to Bodrum.
Final point - it's generally a degree or two cooler than Bodrum.
Its quite expensive but, the Marina is 5 star and has all facilities you might need.
We like it as a stop over for a day or two when checking in/out from Greece.
Only thing we struggled with at the marina was gas replacement but we were pointed to a depot in town near the Mosque who sorted us out.
Havent had any work done but there is a large yard there with several yacht service companies operating. Theres also a reasonable chandlers.
The pool and pool club are very nice, as is the sea water swimming "club" on the breakwater. Its a great place to chill out with a beer and watch other boats sailing by or across from Kos. We havent found any decent beaches so if you fancy a swim the breakwater club is the best place IMO. There are steps into the water but its not for the feint hearted if theres a bit of a swell on.
Marina office staff helpful as were the mooring crews. (3 guys to help us moor up - luxury !)
Last time there I asked for a Blue Card but there was no real interest from any of the officials and we didnt need to pump (or pretend to pump) anything in order to keep the Poo police off our backs.
You can check in and out from 1 new building containing Police, Harbourmaster, Health officer and Customs and using the marina as your agent. Just be careful about timing, it took us a full day to clear out last year because we missed the "window".
Town is a bit scruffy and touristy/brash but there are one or two semi-authentic restaurants and we enjoyed eating there.
I didnt find noise from bars/clubs too bad but both times weve been there weve been berthed inside the outer breakwater. Its certainly nothing like as noisy as Bodrum which I detest
One last thing - dont use the Turkcell shop in town unless you know exactly what you need.
They ripped me off by selling me a SIM for my UK phone which was later permanently blocked. This was before I found out (from Turkcell in Datca) that non-Turkish phones are frequently locked in this way. Im sure they must have know this would happen. I will be using GymSIM next year.