To P-Valve, or not to P-Valve, that is the question.

My kidneys like to go into over-drive as soon as they get anywhere near
water, so I'm wondering about whacking a hole in my new dry suit and fitting
one of these.

On the one hand it goes against the grain to put a hole in a new suit which
then has the potential for leaking very cold water over one's most delicate
bits. I also wonder about how bulky the fitting glued inside the suit is;
is it likely to dig into your leg as you drag yourself back over the side of
the boat? How fiddly is it to put 'on' (yes, I know it depends on the size
of what you're putting it on to)? How frequently do they leak between the
condom bit and flesh bit, or between the condom bit and the pipe bit? There
must be some dead space between the flesh and the outside; how easy is it to
purge this afterwards, without pouring it down your drysuit leg? Balanced
or not balanced? Is there any detrimental affect on your wedding tackle
through being strapped into a condom for hours on end? What happens if you
forget you've fitted it and roll your dry suit off...? How easy is the
valve to turn on and off on the outside of the suit; any chance of
unscrewing it too far and loosing the nut into the depths?

On the other hand, it does sound very nice to be able to relieve oneself
under water, and not have to worry about that desperate exit and rapid
de-kit in order to bare your entire shivering torso to the atlantic gale and
take a leak.

Any advice please. Are there different makes - are some better than others?
How much should it cost to spend a penny? All I've seen so far is a pdf for
the halycon version.

thanks,

M.

(This is a serious post; I'm not taking the piss.)