Re: WGS speakers. Who has made the switch and why?
Heh, Metal Maniac's rant on WGS speakers encouraged me to A/B the G10C/S speakers with my Celestion G10L-35s in my Vibrolux Reverb. Folks mention that WGS speakers seem to be darker than Celestions and while I only have limited experience, I can't disagree at this time.
The G10C/S has some nice qualities. It's a warm speaker, it's fat, it's smooth, it has a really full lowend, it's extremely punchy and it's very well made - no cone cry or weird artifacts present. In comparison, my Celestions were more preferable to me... I liked the midrange, the clarity, the treble really matched what I felt Fenders are all about (even after using the bright switch on my VR with the WGS). Because of the more emphasis on mids and treble, the bass wasn't as prominent which felt like it matched the voicing of the cabinet and the amplifier to begin with (bass can get overwhelming very quickly with this amp). For this amp and this application, I felt like the WGS colored the sound too much and I felt like the Celestions really just breathed more and fit the character of the Fender in a more natural way.
The reality is that it's all about matching the specs of your speaker to your amp. The lower efficiency and completely different voicing of the Celestions were what I wanted to hear even though they were what was in there initially and I hadn't realized just how good they were until I had tried something different. I think in the right amp, the WGS would have been killer. And the comparison wasn't very fair to begin with... the G10C/S has a smooth cone and the G10L-35s have the more traditional rounded cone so that makes a big difference alone. I bet the G10C would have been a closer match, but I was so happy going back to the G10L-35s that I didn't even bother trying anything else.
One notable thing is the weight. The Celestions are a lot lighter and the WGS ones feel much more substantial. I think the WGS speakers had a bit more punch, but the overall voicing of the Celestions made them keepers.
Hope that gives you a little more insight than what you started with anyhow

I'm a bit biased towards Celestions honestly. I've tried other speakers before (like Weber's Blue Dog and Silver Bell) and Celestions just sound right to me (I think it's because it's a british UK thing). I've had Vintage 30s, my current Vox uses an Alnico Blue, I've also had the C80 and the G12H30 and they've all worked well for me.