Boss VF-1 Effect Processor

I have a Boss GT-5 (guitar effects processor) and since I've explored 
it alot, I was searching for another device to gain a new dimension 
in producing sounds with my guitar. Recently I saw a post from 
someone trying to sell the VF-1. Since I'm new in this forum you 
could help me by answering to my questions:
- is the vf-1 any similar to the GT5 (same efects?)?
- is the vf-1 guitar-oriented?
- does it makes sense to work with both devices processing the sound 
of a guitar?
- does amy of them mske the other one useless?
Many thanks, 
best regards,
       Luís