I've used a Kong Ghost quite a bit with both a Black diamond Vaporlock and the DMM Shadow Locker (and others), in both lead and follower belaying on various moderate trad routes and in the gym. The Kong Ghost, generally works best with ropes in the 9.5-9.9 range in my experience. It tends to stick up with 10.2 ropes and higher. It also has some subtleties inherent to giving a smooth belay. You have to "angle" the rope when feeding to the device's internal angle.
I found that when belaying 1 or 2 seconds I much prefer the Reverso (original model) to the Ghost. I am going to order one of the new Reverso 4's! I am also going to order some of the new light Grivel Plume Locker's!
I feel that I always need at least 3 lockers for lead multi pitch routes -- 2 for belaying the second and 1 for being clipped to anchor.
Also, for all the "skinny people" who climb trad 12's complaining about **anything** - just take a powder ;)
Just a quick anecdote: I've been climbing on some of my gear for 20+ years and while much of my rack had been updated, most of it I had never felt the need to change. One of my climbing partners on a trip this past April simply looked at my old gear and suggested that as I have some connections on cheaper gear and the ability to upgrade my rack and draws that I do so. Over the next couple of months I replaced all my cams with new X4's, C4s, and dragon cams. All my racking biners were changed out with heliums or oz's or hoodwires, and draws with both Heliums and Anges, minus some of my trad draws that have original wiregates on them. I can't believe the weight difference. Add to that lighter / skinnier ropes and the difference on a long approach is huge. Without using a scale, its got to be close to 7-10 lbs that were lost carrying a rope and rack of doubles.
Its made me think back to the days (15 yrs) that I climbed with two sets of nuts, a couple of hexes and tri cams and four cams BD .5-#2. I climbed on that rack hundreds of pitches (many of which necessitated back cleaning) but also my hardest pitches. No wonder. I was carrying 1/3 of the weight. I might make it up pitches far faster now carrying a complete rack of doubles - plugging cams and gunning for it - but the simplicity of it could not have been beat.