After experimenting with both:
FreeTube
-FreeTube doesn't always find exactly what I'm looking for.
-It's easy one-click downloading.
-Names the file name with arbitrary numbers and letters (youtube source I think)
JetVD
-JetVD seems to have better search results.
-JetVD allows you to download the videos in 3GP, FLV, or MP4 in varying amounts of quality.
-It takes a few seconds or a minute to "analyze the video" before you choose what version to download.
-Sticks into notification bar download progress, and makes a sound when finished downloading
-Maintains the name of the youtube video as the file name
Video quality is about the same, possibly slightly better on JetVD. However, Jet VD allows you to download in low, mid, high, or 720 p video quality while FreeTube is just one. 720p download (if the video allows it) is much much higher quality and better full-screen.
I'm sticking with JetVD because their searches provide more accurate results, plus the option for video type and quality level is good too.