Originally Posted by
guv1976
While it would take a little longer to get to LGA by train, it's not that much longer. The LIRR takes about 10 minutes to get from Jamaica to Woodside, where you can catch the (free) Q70-SBS bus to LGA. That bus makes one stop at the big Jackson Heights subway station, and then operates nonstop to LGA. So if LGA makes sense on a particular trip (whether on AA or DL), I think that public transportation could still work for you.
Your logistics are spot on but this is a hassle especially if you have luggage. You would almost be better taking the LIRR to Woodside and then taking Uber / Lyft to LGA. When I'm in Manhattan from work and have a late afternoon flight from LGA, I take the N/Q to Ditmars and then Uber from there.