Well I got a Vox Valvetronix VT15 for Christmas (my first amp) and I've recently read that there's a pedal sold by Vox just for this amp to change channels and bypass effects (Vox vfs5). Now does anyone have any experience with this pedal to tell me if its worth it or not? Because on some songs I want to have distortion and be clean at different times in the song and I can't just stop and change it, you know?

So any help for me?
Yes its worth it if you yourself said in the middle of songs need to switch "channels" and if you plan on keeping this amp for longer than a month, get it.
+1 that's a very good option to have.
Dean Icon PZ
Line 6 Variax 700
Dean V-Wing
Dean ML 79 SilverBurst
MXR M 108
H2O Chorus/Echo
Valve Junior (V3 Head/Cab and Combo)
VHT Special 6
Phonic 620 Power Pod PA
Wampler Super Plextortion
Line 6 Pod HD
Yup, I used to have the Vox AD50VT and I had the pedal also. Very useful for turning effects on and off, and switching channels in the middle of a song.