What is the difference between Lionel polar express trains 6-28653 vs 6-18784

Engines are identical with exception that the engine in set 6-81101, the 10th Anniversary set, has the added detailing of seperately applied handrails while the handrails on the engine in set 6-30218 are cast in the body shell. Also, the 6-81101 set has additional sound clips from the film. The 10th Anniversary set loco also has 10th Anniversary decals on it. The cars in both sets are identical except the 10th Anniversary set cars have 10th Anniversary decals on each car. Only other difference is the 6-81101 10th Anniversary set also includes a Polar Express girder bridge.

Both locomotives running capabilities and performance are identical since they have identical motors and mechanisms. 

While no longer available on Lionel Web, there was a conventional set also.  The 18784 I thought was listed as the conventional engine with whistle.

You will find 3 models in the market.  The first is the original conventional with whistle.  It had the handrails.

The Lion Chief version which is remote controlled via its own remote.  This had less detail, but electronic movie sounds.

The LC 10th anniversary, which is LC with remote, but added back the handrails.  G

Don't have any personal experience on this topic. However because of some guy named Mario continually tempting through email with excellent deals. I'll be able to let you know the differences in few days. Under $300 delivered to my door for the 10Th Anniversary Edition Polar Express  rtr set. Now I'm almost positive since I pulled the trigger on this set Lionel will announce a LionChief + release for the 2015 Christmas Season.

But, Oh Boy! Nothing like The Polar Express running a loop at the foot of your bed to guarantee happy dreams at night.

To further confuse things, the set below has been on the Lionel shipping schedule for quite some time but is not in any catalog, at least yet.  Maybe 2015 Christmas catalog ?

Wow thanks for all the helpful information. Now I just have to find the set that won't put me into the budget doghouse with the mrs!

Lets go eBay!

Here's the link I used to Mario's current web store promotion. Good through 2-28-2015

Remember to use the proper promotion code and as usual free shipping on all orders over $200.The set wieghs in at 18 lbs so I'm pretty sure that would be a substantial savings in shipping if you were to buy it from a private party. Plus buying new with the Lionel warranty and backed up by Mario's supperb service is another bonus.