I've been very impressed with the PRS SEs I've tried and think you've got a great guitar. Regarding differences, I think every PRS guitar is the best the company can build given its price point.
With that, like most things there is the law of diminishing returns, so things like spending more time carving a top and using higher grade wood typically increase the cost at a higher ratio than the improvements in tone and playability. Thus, in short, there is an improvement, but, say I don't think a $5K PRS won't be ten times better than a $500 PRS (that is a subjective statement).
More importantly, I don't think a properly set up SE would ever hold someone back, and there's no need to feel you need a more expensive guitar to get where you want to go musically. However, a guitar is a creative tool, and part of its appeal is its ability to inspire a musician to continue playing and exploring. For some that guitar is something like a PRS SE, for others its more akin to a PRS core line. The trick is finding that one and hopefully having the means when it shows up.
(Personally, the guitar that inspires me most right now is a 2008 Mira, and I like it better than some significantly more expensive guitars I tried. It just seems to fit).