Here's my take.. given that I am actually residing in Punggol for the last 2 years or so ...
It was initially one of the last places on our list but after looking at more than 30 different units throughout Singapore, we chose Punggol for the following reasons:
1) Still undeveloped but not too undeveloped. The earliest settlers in Punggol are at least 7 years old. That is the age of the property we purchased from the resale market. So it is not too old.
2) The price we paid was relatively expensive at around 400+ for a 5 room but the view was unblocked (for now at least), high rise with good year end wind (save at least $60 off my air-con bills for about 2 quarters a year).
3) KPE is accessible to town in less than 30 mins and the LRT / Train is rather convenient .. not so now as it is starting to get crowded but we beat the crowd by being a bit earlier each day when going to work.
4) The landscaping project in Punggol is still one of the better ones than other mature estates. Thus, we get good parks when going for a romantic stroll or for a run to keep fit.
5) At least, we get to see new items being introduced from time to time ... McDonald is finally here, the Community Club is up... there is Popeye, Uncle Leong, a few uninteresting entertaining facilities like prawn fishing... ha
6) The resale value will be good when we want to downgrade to a smaller flat as me and my other half gets older ....
7) On weekend, we get the excuse of not going down to orchard because it is still relatively far (having to change MRT lines ... me and my lazy excuse) and our flat is very cozy ...
8) The HDB blocks are quite well designed and not too clutter at this moment (cannot speak for the future)
9) Punggol (other than west coast and east coast) has interesting beaches under development ... good place to be when it is fully developed
10) Cannot really think of any but I am looking forward to more new malls being opened as there is only one pathetic Punggol Plaza near to where I am staying
...