Bursa or Antalya?
 

This is just something I was wondering; and I'd love it if I could get some help on it.
If I were to go for a week long trip to Turkey, with 4 days in Istanbul and 3 in a different city; which one would be more preferable in your opinion?
Bursa or Antalya?
I've researched about the two but I can't seem to makeup my mind.
And there will be children included in the trip as well.
So which city out of these two would be more worthwhile for a small family vacation in June with a 4, 12, 15 and 18 year-old?
In terms of relaxation, sightseeing, activities, scenery etc.

Antalya, because you'e got the beach as well as interesting sights within reach. Bursa is interesting but more suitable for a shorter stay imo.

Have a look at the Fethiye area too. It's only an hour by road from Dalaman Airport.

Fethiye is a lovely working town, but tourism blends in effortlessly, it's good a lovely marina, and restaurants galore. And very scenic.

It's like the hub of a wheel, with places like Gocek, Hisaranu, Oludeniz, Calis Beach very close by and easy to reach by dolmus.

Antalya has a similar vibe, and the airport is only a few KMs east out of town.
The walled old town of Kaleici is in a waterfront area of the town, and is more-or-less traffic free. It's a lovely place to wander around. The seafront in Antalya is well above sea-level, with an old tram running along it. Very pleasant, and great views.

For somewhere completely different in Turkey have a look at Cappadocia.

Antalya: tons of sandy and pebble beaches, tons of antique theatres and temples, no breathtaking Islamic monuments.

Bursa: interesting mosques and other Islamic monuments.

Antalya is very touristy, with tons of Western Europeans and a lot of Turkish shopkeepers and hotelkeepers coming from other areas of Turkey.

Bursa is typically Turkish, almost no tourism, almost all inhabvitants are local people.

Both have a mountain called Olympos in the neighbourhood and both mountains can be reached by cableway.

Thank you so much for your responses!
Yes, I think this pretty much cleared it all. :)
Thanks once again!