Your opinion of which engine to purchase

How about one of the new ES44AC's in the 2015 catalog? You may have just enough time left to order one, if you hurry. Nothing like the latest and greatest.

With so many products on the market you are only going to get info from someone who has bought one or the other.  I have two of the Legacy Heritage SD70ACe.  They are in my opinion excellent runners, smokers, sound equipped and have very good details added.

I myself don't really care about smoking diesels, but it seems that the prototypical ESAC44 won't have much in the way of smoke. Maybe a first generation diesel would be more prototypical as a smoker.

Definitely the Lionel ES44AC.  Love the new ones, but the better ones were the Die cast versions IMHO.  Diecast ones seem to sound deeper and richer, smoked real good too.

they are all "ready to be on the track". why would you think different?-jim

I think he means one that he can buy today.

We have both the Legacy GP-7 (UP), GP-35 (NYC) and the Baldwin S-2 (C&O). All are great.

They are also scale but much shorter than the ES44 so they don't look wrong on sharp curves.

Can't really go wrong with any. Great detail, great sound, great slow speed.

The UP does have some cool additions that most legacy diesels don't such as mars light, directional marker lights and wheel grind sound effects. These have been out of production for quite some time now but they do show up on Ebay.

In that case it may be more a matter of what your LHS has left in stock, or what other dealers have left in stock.

Nice choice IMO.