Beware shiny jet syndrome!

Ultimately, you have to answer for yourself what is better for your family.

Understand that going to F9 and getting more SIC time but in a larger plane will not be viewed nearly as well as getting PIC time in an RJ by any of the larger majors (AA, UA, DL, WN, FDX, UPS).

What that means is that going to F9, in a best case scenario, is getting you almost no benefit in improving your options at other carriers and worst case is putting your entire career at risk. (based on the current environment)

I personally believe that the current times we are in are some of the best times ever to be a pilot that is looking to move up in his/her career. While the specific values that the big airlines place on experience across different aspects of our careers are not precisely known, the general values sure are. They like PIC time more than SIC time. They like 4 year degrees. They don't like multiple training failures. They don't like DUIs. ETC... Changing airlines and not getting any improvement in the areas the bigger carriers care about and risking getting negative attributes they don't like, means you are looking at this new carrier as your potential last carrier. So, is that new carrier one you are comfortable with being your last carrier?

The decision you face is an absolutely easy one to me!