Go with your instincts if you feel that way about the karma generating from those folks... Every time I decided NOT to trust my instincts consistently resulted in painful revelations regarding the truth about people, places and things after committing, and almost universally experiencing profound disappointment and sadness as well. Your instincts are almost always looking out for you exclusively although there have been a very few, and rare exceptions to this rule...
In fact, those were so rare that at the present time I cannot recall any of those exceptions at all! I got bad vibes about Can Am also some years back, and didn't bother to follow up with them after having a phone conversation and letting my instincts talk to me, and I believe I made the correct decision but then again and however unlikely, things may have changed with them since back then although I doubt it.
Good advice from Henry. Even if someone else may end up being happy there...you have to deal with your own ethics, morals, personality and character trait match ups, life goals, future training, and so much more. I turned one down recently, not because of bad vibes, but because it wasn't the type of work I could see myself doing everyday for the next 10-15 years. And it was only 10 miles from my home, 40-50 hrs per week, decent pay and benefits, and opportunity for more training and certifications. Just didn't feel right for me.