The Jointed Rail version allows full editing, merging, etc., as we've always done. The N3V version is locked down. You can edit the route, but it's an alias and you can't merge it.
With the full Jointed Rail version, I merged in Rich's (Scratchy) Eagle River logging route in to Legends of the BN 1 and 2 which I have. The BN routes act as a mainline railroad which I heavily modified by adding in passing sidings, and changing out some of the towns so that they don't duplicate too much, where as the ER is a lengthy branch line with forest industries. I take an interchange load up to the mainline and exchange wood products for other goods plus run passenger excursions over the length. The operating session I created can last for hours before I have to quit. It's up to you, but I paid the full price before and got the routes from Jointed Rail rather than be hamstrung with the DLC version.