I would not slam the rider or the bike yet.
As mentioned tire pressure seems to be a bit important on our heavier 14 RTs, but could be important on the other machines as well.
As for the wobbly, there are a few ways to consider this description. It could be rider induced, it could be chassis instability. Before going crazy, get the front wheels aligned. Our machine was crap in corners when we first got it. At first I thought it was me. Over controlling and so forth. In the end, I focused on how it felt when cornering. The bike would be fine on turn in, then mid turn as the bike became more set, the suspension compressed and bump steer played havoc in unpredictable steering. The machine would dart to the inside, causing more control to the outside. Then it would happen again and again until the corner ended.
I have not had the laser alignment yet. I took a guess and cranked some toe in into the tie rod. It got better. Even the wife noticed immediately. Better but still a bit twitchy, I added a bit more toe in. Now it corners a smooth line with little effort and no corrections.
May not be the problem, but is easy enough to work out. With a good setup, I believe these machines can be pretty stable, even without the add ons. The add ons will likely improve a good machine more than they will as they mask the root cause.
PK