A common theme on forums is people telling others stuff along the lines of, "anything better than XYZ would be lost on you unless..." and then they go on to outline some arbitrary reasons why so-and-so doesn't deserve or hasn't earned the right to whatever it is that they might want. Like you've got to pay your dues, or something silly. A good set of wheels can and will make a difference, so don't take it to heart when anyone tells you, whether or not it's with good intentions, that you're not good/experienced/skilled/fast enough to justify having them.

That said, if you're planning on the SL5, there's no real rush on better wheels unless you're aiming at a decent discount from the shop (or if your riding season is limited and you don't want to piss away half of it, wondering how much more fun it might be with kick-ass wheels ).