I love my Spitfire.
This was my first airgun, got it new for my 18th bday in 2005. .177 full length barrel, one hole groups at my 35 meter range.
John blueprinted it a few years ago when I lived in Devon. Still working great.
I'm getting 60 very consistent shots per fill with the buddy bottle at 11.2 ft/lbs. As greenwayjames writes, very handy to have a buddy bottle in the Barbour pocket.
I also have a HF. The buddy bottle charging with the clever pressure indicator suits me better.
I had two Firebirds, great too, Ped has my .20 barrel now.
But I often forgot to close the sliding breech cover and prefer the even greater simplicity of the Spitfire.
For servicing: send to John 100%. It's worth every penny. I have resealed a few, yes it can be done, but you often still have a slow leak and this is not the case after the gun has been to John.
Cheers