Mostly the cosmetic differences you see by sight comparison. The pots are exactly the same in both banjos if what I have heard is correct. I have a 36 and they are good banjos for the money.

Bobby

The main differences are the price and the scale length.

The Elite has a longer scale with 27 3/8" wich can feel much different if you are used to shorter scale lengths.

I had some old German banjos with longer scales and it is a bit more challenging if you want to change quickly between far registers, at least if you are like me not used to it.

Roman

I have an RK77 Elite and a 1978 ODE Style C , both have long scale lengths. My TB-1 conversion has a normal scale length,, plus I have a classical guitar and 3 steel string acoustics, all with different necks. It takes me 15 minutes or more to feel comfortable when I change from one to another.

If the opportunity presents, try playing ~27", ~26" and ~25" scale banjos of similar types with the same string sets in a single session.

Banjos have relatively long scales and the extra inch or two amounts to about a quarter inch at any given chord location.  The spacing difference is a minor thing that disappears with a capo.  YMMV.

I have noticed that the longer scales have greater volume, pop, and the strings feel more compliant.  The string feel and pop are sweet. 

RK Elite has a one-piece neck (not counting peghead ears). RK36 has a grafted headstock and stacked heel. This contributes to lower cost by getting more necks from less wood. The wood in the Elite may be of higher grade, or at least aesthetically superior. The mahogany(?) (sapele? something else?) in the RK36 neck is not necessarily chosen for match of color or grain. I guess the stain (or toned finish) helps even out the appearance. The mismatches I've seen in RK36s in person and in photos have not been large. Mismatches in the maple RK35 before the change to a dark brown stain were sometimes pretty significant.

I believe the RK Elite has Gotoh tuners.

But, yes, the rim, tone ring, flange, tension hoop and other pot hardware are the same. So it's hard to point to $800 or so in differences between the two banjos. Rather than wondering why the Elite costs as much as it does, I've always wondered how the 36 can cost as little as it does. A whole stage-worthy bluegrass banjo for less than the cost of US-made neck.