I would say that turning down the job would definitely not give you a negative reputation. In my opinion it actually could strengthens you as a future candidate. We really value people that are dedicated, loyal, and will do whatever it takes to get the job done. It is what we try to gauge when we interview...which is definitely not easy to do. If I get a resume that I can see you have worked 3 different jobs in the last 5-10 years, I probably wouldn't even give a first interview. My first impression is that this is someone not worth hiring. By time they would get trained and understand how we operate, they would already be looking for another job and then we would have to go through the whole process again. Training employees is very expensive and negatively affects productivity. Here is something that happened to us 2 years ago. We hired a great engineer that was with us for 2.5 years. He got frustrated with the type of projects we were doing and he ended up taking a different job for more money and also did projects that interested him more. After 6 months, he got burned out because it was not what he signed up for. He was working occasional 70 hour weeks and he ended up doing more babysitting than engineering. He sent me a text asking to see if I could pull some strings with the owners to get his old job back. We already filled his old role and the owners weren't very keen on bringing him back, so we had to turn him down. I believe shortly after he sent that text to me, that firm got bought out and the situation got worse. The last I heard from him, he quit that job and now works for the firm he was at before we hired him. This story is why I said the grass isn't always greener. However, sometimes it can be. I would highly recommend to you to make a list of all of the positives and negatives and make the decision for yourself. If you don't see yourself at either place long-term, it might be best to stay at what you are doing now and wait for a better offer. Maybe your next job will actually be your dream of being your own boss.