We've done two Neilson holidays - Messini in 2016 and Alana in Croatia last year. Both of these have short transfer times from the airport - about 40 minutes.
I had checked out Neilson holidays for a couple of years before we went but always felt they were ridiculously expensive.
However, I wish I'd done them years ago. Absolutely fantastic for adults and kids alike. So much to do if you want to, or you can just do nothing and relax. Staff are amazing - the various instructors (sailing, tennis etc.) are enthusiastic and genuinely want guests to have the best possible holiday. Food was really good at Messini but disappointing last year in Croatia, as was the accommodation. They're doing a revamp at the moment in Croatia, including a new 50m pool. I loved the location of the resort with the national park as the backdrop and walking distance to the local town with several options for the non-inclusive nights.
Messini was also nice but a bit out on a limb in terms of the location.
You really don't spend a lot whilst you're there so, whilst it seems expensive when you're booking, it actually works out to be good value.
Trip Advisor is a great source of information on all the Neilson resorts.
Enjoy if you do decide to go.