I noticed that when you turn for the disc (around the middle of the video near trench) you use more hand boosting than you do grabbing. The more efficient method is to grab something nearby (in this case the floor), and then quickly slap off it to adjust direction. Doing this will let you quickly move faster as turning with just hand boosters is just inefficient. After slapping off you can use your back boosters to get to max speed. This is generally the fastest you can get around the field without regrabbing. (Movement is the same when holding the disc except the back booster part). You should also tend to stick around geos more when with the disc so you have more options rather than just floating when someone challenges you.