I'll chime in on behalf of the Callaway X. I got one for Christmas last year and love the club. I took one out for a round last September and was consistently knocking it 20 yards past my Titleist 975J with better accuracy. After that round it immediately went on the Christmas list.
I also played a round in August with a G5. I just liked the way the Callaway set up for me more so than the G5. I hit the G5 better than the 975J, but I hit the X better than the G5.
The X is now only $199 new which seems like quite a bargain, but I'm not that familiar with comparative club prices.
Just my $0.02.
I think you will find this is very much a Ford vs. Chevy type debate. Both are fine products and you will just need to find out which one is best for you.
Good luck.
Let us know what you choose.