Well,for starters, the lei is usually harder to find and more expensive than the jar.The jars usually become very agro as they age and grow,not sure about the lei as far as that goes......
I don't have any but there should be plenty in arowana media lounge.In my opinion they both look similar but the jar seems to be less slender than the lei.
Jardini have a beefier/taller body shape when they get larger. Jardini's also have a darker body color. Lei's are a bit silverish in color. Leichardti are much hardert to find. Leichardti seem to fit into communities easier than jardini's. I have a leichardti...i did have it housed w/ a blk and silver aro and various cichla. BUt i have sold the black and silver. I perfer a lei over a jar in all aspects.