We've just returned from 4 weeks at Villas Marlin. Overall, our holiday was fantastic and we enjoyed staying at the Marlin, but there were a few issues that we had during our time there.
Pros of Villas Marlin: Location - set on a fantastic beach, next to Kukulcan Mall, only 5 mins walk to La Isla; swimming pool - kids pool felt like our own private pool most days, sun loungers always available; actual villa (439) - some nice features including fast free wireless broadband, 3 flat screen TV's, nice art work on walls, nice view. Alvin and Ferdy were very helpful - any issues we had they sorted straight away and checked if things were ok. Being able to email a shopping list and have everything there waiting for us was great. Water cooler / heater very useful. Price - very good!
Cons of Villas Marlin: There appears to be building work going on almost constantly. For the first two weeks, the apartment next door was being refurbished, this meant builders constantly on the roof in front of our balcony and building noise (however, it never started too early and seemed to finish quite early). There always seemed some area shut off. For a family of 5, fully equiped kitchen includes an oven - it didn't have one (should have read details better). You need to good control of the ants, there are lots of them - we had to do a good bug spray every couple of days and ended up keeping most food in the fridge, only had one cockroach in a month (had far more in posher places in different parts of the world - you expect a few, you're in the tropics!). Playground has gone - our kiddies were looking forward to this.
If you want a 5* Cancun experience, do not stop here. However, if you want fairly decent, cheap accomodation in (what we think) the best location in Cancun then this is the place for you! For us, the location made an outstanding holiday.
Use the buses - we regularly went to El Rey ruins (fantastic) to feed the iguanas and went downtown. Good playground in Palapas Park, kids can play whilst adults can sit and have great food from the stands. Visit Crococun Zoo - excellent animal encounters. Never accept the first price a taxi driver asks for. Shop at Chedruai, its cheaper than Walmart. Spend at least a night on Isla Mujeres watching sunset on Playa Norte. Kukul Kids is a great soft play centre for toddlers - visited many times.