It's very easy to see that jam's character was heavily influenced by the original shotokans in street fighter. Jam is nothing like them, in some ways..in the way that it's guilty gear, but at the same time she's looking for the exact same things and they are and going about making them happen in similar ways , minus the reliability on projectiles. Her fundaments are that of a shotokans imo, except no projectiles.
you gotta understand that difference between playing jam, and playing jam at a high level are whole worlds apart.
on the basic level jam is perfect to start off with, high damage easy combos easy inputs, fast pokes with nice hit boxes 2s ^__^. she has insanely strong area's in her game but at the same time she has a very hard time of getting to the point where she can let it shine due to her extremely limited range.
I started on jam and had such difficulties at the start, I'd just rush and rush and get owned over and over. Until I started realising more and more about her strenghts.
With jam you learn all the finer details off gg fast, because you are FORCED TOO.
It's not like ky and sol were you can just stay at bay and abuse projectiles land a combo and win, this is extremely limited in terms of what you will learn imo.
You can repeatedly do the same shit over and over and still win without learning any of the finer details. With jam its completly different, you know her strengths, her abare is crazy her constant abilitry to keep you on defence, in fear of her abare is scary for the opponent, her frame trap/high low/tick thow/bait rushdowns can be really overwhelming, her okizeme blah blah...BUT THE PROBLEM IS you just don't know how to apply these things.
You are forced to learn the finer details, and fast. Learning how to control space and positioning are learned so fast with jam, then eventually you will learn when to break from these things and go on the offence and how to maintain it and you also learn the importance of breaking your offence to go back into space control and baiting. and eventually you will start to really understand how to bait and punish.
Most of the other characters imo always have one thing about there game that stops you from learning how to deal with certain situations because they have the ability to abuse their strengths and always have this one thing they can fall back on. jam doesn't really have this, she really has to work for it alot more than others, forcing you to gain a much higher level of understanding of the game then you could ever get by just abusing the broken strengths of sol and ky. you wanna learn how to play well, play jam.
Im not saying that playing the other characters you won't get good. im saying you can start off as sol and ky and win and learn the game slowly. or you can start of with jam and not do so well but at the same time learn the game much faster because her playstyle forces you to understand so many aspects of the game.
Jam at a high level is what guilty gear is all about, at this level she is imo, one of the most difficult charcter's to play.