What's the difference between a MTH Railking & Premier Caboose?

The big difference used to be interiors, but your new RK caboose has one, so that isn't it. The other difference I am aware of is trucks - Premier trucks have the coupler on a swivel mount, RK trucks mount the coupler rigidly to the truck. You can check your trucks to see how the coupler is mounted. 

There is just a small difference in painting details, really nothing else to justify the extra cost.

Mostly the color of the box and about $10!

I thought the Premier cabooses had opening doors.

There is not much difference btw. The premier and railking cabooses. It has been this way for some years. They are for all intent the same car exactly.

Sprung trucks, perhaps?  Aside from that, very little discernible difference.

Some of the early Railking Bay window cabeese were no different than Premier versions.

My RK Cabooses have sprung trucks. Only difference I've noticed, other than the price and color of the box, is the addition of air hoses on the couplers. 

My Railking Imperial Y6B Freight set included an N&W Caboose with air hoses on the couplers but was packaged in a Railking Box. I believe it is a Premier piece just in a RK box. I was unable to find it in the MTH database leading me to believe it is a Premier car they made and stuck in RK boxes. 

Only difference is Premiers have painted grab irons and window trim.

Nothing else.

Doors do not open on MTH, only on Lionel "O" M53's,BW's & NE's.

Some of the LIRR MTH cabooses are not really correct in appearance and road numbers, but we'll take what we can get I guess.

Accuracy dosen't count with MTH only with Atlas O & Weaver.

I see a 15% less bulk in my RK FA units versus a Premier B full sized.

Regarding cabooses, I have a few RK's, Premiers and Lionel. They all look rather good together.

I can't see a difference. Handrails are painted on both. They have the same trucks and air hoses, etc.

The LIRR isn't accurate as SIRT said, but I like it all the same. 

virtually identical so I am happy to buy Railking versions

virtually identical so I am happy to buy Railking versions

I had a close look at a Rail King bobber caboose vs a premier model that I both have. They are from different years, so I don't know if later Rail Kings were also changed. The only differences I could find was that the premier base casting had screw bases that could hold a KD couplesr and there was a figure inside. I know some Rail Kings also have a figure, but mine does not. Another thing was that this bobber came in a set, so maybe the separate sale versions have them.

I had a Rail King Scale Burlington SD-9 here for conversion a few years ago, and a Premier version at the same time.  I think the only difference was the whistle was plated on one of them.

Nothing that justifies the additional price, I noticed the same is starting to happen to premier diesels.  Case and point the latest Premier version of the Long Island VO1000 switcher.  It’s nothing more than a Rail King model in a Premier box plus $100.

So I'll not be pre-ordering these models, instead I'll waste till they come out and then decide if they’re worth the added cost.  Just MHO!