Registering unattached or with and "umbrella" team

So it is just about that time to re-register. With my Local Masters Swimming program (NJ), I can register as unattached or with the LMSC's "umbrella" team (GSM). The LMSC states that with the umbrella team I can swim relays (with other swimmers from the GSM group) unlike the unattached option. Just trying to figure out any other pros and cons. Last year, my first year in USMS, I did go with the umbrella team, however I never opted to swim in a relay. I currently workout alone (no club or workout group), but am entertaining the idea of someday joining a coached club or workout group. Are there any issues switching to a team mid season? -Mark