I have had my Vixen Porta II for a couple of years. I bought it online from a US supplier when it was on sale ( think I paid $199USD for it, back when the AUD was above the USD) - and frankly Steve's price could not complete even with shipping. I also have a guide handle for it which is very useful, which I bought direct from the Japan maker but it's also available here:
http://agenaastro.com/kokusai-kohki-...-ii-mount.html
I have the JMI Train-n-Track motors on my Porta II, and this means no fiddling around with the slow mo cable knobs:
http://www.optcorp.com/vixen-tnt-tra...ii-mounts.html
I have used just about all my scopes on it. It has a Vixen dovetail mount of course. The Az and Alt bearings are adjustable and can be tightened up. The mount is pretty good at holding a scope at a particular spot but still easy to move against the clutches.
I have a ES ED80 Triplet APO which I use on it as a grab and go setup. I have also had 100mm short and long (f9) refractors on it when I owned them, and it didn't even know they were there. I used it to test the setup of the 127mm iStar R30 f12 that I built, and at 1467mm focal length it could still be used but trying to work around the zenith meant avoiding one leg. No clearance issues with shorter focal lengths. The iStar 127 is pretty heavy for the PortaII (at around 9kg all up) but it handled it ok, but balance becomes a tricky thing.
The JMI motor drives are easy to use, and run off 12V (from the supplied battery pack or from an external supply). You just find your target and then adjust the Alt and Az motor control levers to keep your target object in the field of view - easy to use. You can also push the fast buttons to slew if you want, or to catch an object that has drifted off for any reason. Much easier than trying to spin those control stalks. The JMI Train-n-track cost me about $250USD at parity.
I have thought of selling the mount, JMI Train-n track and handle from time to time but its just so handy to have and use that I can't let go of it. Even though I am mainly imaging these days it still gets used for visual work, and quick looks at comets, ecilpses, etc.
Hope that helps.