If you are serious about your playing, and you are serious about your gear, you will be taken seriously in the studio. When a producer or client sees a guitarist walk in with top gear, an immediate message is sent out. That message is, "I take myself seriously, I take my playing seriously." But shouldn't the studio have everything I need? MAYBE. I wouldn't count on it! Be a hero and be prepared! (Thank you, Boy Scouts of America!) Some of these will be obvious. Others not so much.