Is coming from USAREC to a nominative assignment bad for career progression?

Please accept this in the intent it is given.... ....friendly and guidance, not an attack.
Your MOS is 25P Microwave systems installer-maintainers YES?

If so, and this is not meant to be mean spirited but, you don't have a lot of upward career progression , you are in a low density MOS, with significantly limited leadership opportunists in MOS.
As such, Id say take every other leadership opportunity possible .. If the Nominative position is sitting in a basement office with three DA civilians at the Pentagon.. Id pass on it.... If the Nominative position has the possibilities of leadership be it, no solders but project or task leadership or with soldiers I think that would be an ok job to take on.

speaking from the perspective of one serving in a nominative position it is an incredible broadening experience. For IG at least, they look for NCOs who have proven leadership experience such as recruiting. So at least from my viewpoint, it appears that you performed very well in a challenging leadership position (recruiter) and were hand picked for a broadening assignment that will utilize your leadership. When you return to an operational assignment, you will have experience that few of your peers do.

SSG (Join to see) while I love the operational assignments as much as the next person I think that a nominative assignment is always good for the career as it means you were selected over your peers for it. However, I do feel that you need to get some operational experience in there as well. So if your next assignment after this nominative assignment is operational you should be very competitive. Then again it all depends on what the Army is looking for the year you go before a board.