Solo boating is your personal choice. That being said, you should think about a few things.
First of all, I read a lot of AW accident reports. If I run across one that says "paddled solo," I think to myself, man, what a fool. It would suck to end up on that page because you were too proud or impatient to bring your buddies. (if you don't mind this then go for it). Of course, some people will call this something other than pride.
Vanatta: The idea that you are 'usually paddling class V solo because no one can help you in there' is a complete fantasy.
1) There is almost always some way to set some form of safety.
2) Even if you can't set safety, there is someone to give you signals and watch your back, help boat scout, etc.
3) Someone is there to help you scout, someone who will see what you do not, help you see your line, and help you keep yourself in check.
4) Try doing big time first aide on your self. Then try hiking yourself out.
So with all that being said, I think no one can argue that paddling class V (or anything) solo is as safe as having your buddies there to watch your back. I personally believe this holds true even in big water/wide channels as well as boxes.
So, with the added danger factor (class V is already dangerous enough, as is the rest of paddling), consider what your possible death/injury/SAR extraction does to the community's credibility. When we ask for more access rights to rivers what will authorities say? "Oh yeah, you are the guys we have to pay lots of money for to do body recovery and SAR missions."
Bottom line is, if you want to paddle solo, go for it, it is indeed your choice. You should, however, consider it more carefully before doing it. The river is a more powerful force than any of us can handle alone. Admittedly, it is tempting to paddle alone when your buddies won't rally. But is it worth it to increase your risk exponentially just because you are too impatient to wait for your buddies? The river is patient and so should you be.
I draw my line at moving water. If it has a riffle, I want a buddy to paddle with. My heroes in paddling are those who run rivers safely, work as a team, and respect the river's power.
People always talk about the 5 essentials, 1) boat 2) paddle 3) skirt 4) pfd 5) helmet. IMO the 6th is your buddy and you shouldn't put on without him/her.
since this is the internet, feel free to flame...