We just returned from Marina Del Sol, Unit 511 staying June 25th to July 1st, 2006. The situation was a family reunion, so I saw Unit 507 and 504 also. This is not a super resort, but an above average condo complex with units that vary in quality depending on the owner. Our place was small, but doable since we are a couple with one small child.
We shared the bedroom and they provided an air mattress with linens for our daughter.
Unit 511 is bigger and fit 4 adults with 1 preteen. Unit 504 has a double bed and a twin in one bedroom. The AC was good in all units except 504. There are furnished kitchens (distelled water coolers) in all so pack some coffee and soup. There is also a mini market downstairs, but not anything to make a true meal out of. I went to the grocery downtown (by Margarita Village) and bought bread and lunchmeat, $6 taxi ride back.
The pool was nice size with nearby bathrooms and a restaurant. Look for the free drink coupon that they give you when registering.
First the negative. This is Mexico. It is hot and humid in the summer months. The service is slower than in the US, so relax, you are on vacation. If you don't check in by 7pm, they leave a key for you , so if you need an air mattress call before or wait until morning. Groceries are expensive, check the prices before you buy, corn flakes at the market were $7.
The positive, the pool restaurant is good and well priced. The massage I got at the spa there was awesome, better than any four-star place in Scottsdale. The Medano beach at Mango's/The Office is rowdy and fun. Lots of good music, plenty of water sports, cheap beer buckets, yummy nachos (try the steak and use up your cholesterol allotment for the rest of the year). The vendors can get annoying, but they'll negotiate better on the beach than in town. Get a henna tattoo, I love mine, though I can't commit to a real tattoo. Watch out for the tequila shot man, he'll have you passed out in no time. He also makes balloon animals, that seem like a good idea, but if you are a parent, you already know how sad the ending can be.
Some restaurants we liked were Nick San (AC and fancy) and Marisquería Mazatlán (no AC and cheap). Mi Casa, a block away was good the first night and not so good the second time, but has some amazing Day of the Dead stuff in their gift shop.
Some fun activities. I loved the Banana boat ride at Medano beach. It is fast, so kids under 10 might fall off. We went for $9 each. The jet skis are fun and we took our 4 year old, very slowly. 40 minutes, for $40 and she loved it. The Buckaneer pirate ship was fun. We got a deal for $50 per adult with a free kid under 10, but I bet there are better deals if you book ahead online. They dance and sing and really entertain you. Lunch is yucky brown tuna sandwiches, but the bloody marys are good. You can buy a better boxed lunch at a deli near the pier for $10. it comes with a huge sandwich (enough for two), apple, chips, and veggies+ dip. Plus you snorkel, so you get the Pirate atmosphere and the snorkeling in one shot. I didn't go to Lover's Beach which is a Water Taxi away from Medano beach, but my relatives did and they said to stay for one hour since there is little shade.Overall, a good place to meet up with friends or relatives from all budgets. If you are looking for luxury, I would say the One and Only Palmilla. But this place served our needs and we had a really fun time.