[allend]

Your coworkers should not and probably will not feel negatively about you looking out for yourself. Speaking from experience from both sides of the aisle. Just how personal relationships work.

The company has invested in you, but you have been investing in the company as well. You won't get the time you spent there back to work on something else.

If you are going to grow or be more challenged more somewhere else, then the future impact will be positive anyway, for you and others. Just be you aren't drinking the new company kool-aid before making a decision.