2500 miles.....excessive....no. 99% of my driving is in and around NYC.....and it does sit idling sometimes because of my dogs needing the AC. The short trips and idling reduce useful oil life. Usually I do it <3000K miles, and I always add a quart of Lucas oil treatment. I bought this 93 Ed Bow with 74K miles on it, and the PO did take good care of her....just not as good as me.
"because synthetic is thinner that regular, you will burn some if you use it early. "
Its not that the synthetic is "thinner".....its that the synthetic has much better anti wear properties, and the the break in/wear in of a new engine will not take place as it should, or it may take longer. On any brand new/rebuilt motor I switch to full synthetic at 2500 miles using either Amsoil, or Royal Purple, or Mobil One.
On the other hand I never switch over a older engine that has been using petroleum based oil to synthetic with more than 40 or 50 K miles on it, because it will sometimes tend to develop leaks. With the petroleum based oil sediments build up in areas that could potentially leak, and then when you switch over to the full synthetic, because of the very strong detergents, and much better flow characteristics of the synthetic it can clean out these deposits, and the seal/gasket area will leak.
All in all.....yes I think using full synthetic is a better value due to extended service intervals. I have sent out samples of synthetic Amsoil 5W30 with 10>K miles on it to be analyzed for useful service, and the reports have always come back saying it had at least 40% service life left on it.