Hi PhilW,
I had a 3 level decompression and fusion of 4 vertebrae in my neck in 2010. So now I have a stiff neck - since 4 of the vertebrae are now one piece. I also acquired spinal cord damage in 2 places (not the fault of the surgeon) which has left me a bit wobbly on my legs - so I tried a Performer 20/26" recumbent a couple of years ago. 2000 miles later and I'm about to take delivery of another - this time using my Mavic 700c wheels and the ultra low gearing cassette and chainwheels etc off my DF bike - a Giant Defy.
I've been audaxing my recumbent - I'm about 5% slower than on my Defy over 100k - but the benefit is absolutely no neck, shoulder, wrist or back pain - just in the legs! So, I'm hoping the 700c version will be quicker and I can attempt some 200k audaxes - which I think are a bit far on the 20/26 wheeled bent.
I cannot overemphasize just how beneficial I have found the recumbent to be in mitigating pain as a result of my spinal injury. But, and it's a big but, it took me a good few weeks and about 500 miles to get to the point where I became convinced that the recumbent experiment would work for me. People were telling me that it was the right thing to do, but it didn't feel that way for a while. It took me a long time to get the neck rest (it's not a head rest) position just right, to find the right padding for the neck rest (Ventisit in the end) and to get the seat angle right. To start with I made some brackets to tip the seat more upright than the manufacturer intended, but gradually reduced the seat angle until I now have it on the most reclined position.
Everything about riding a recumbent is odd, and totally alien to begin with. Buy one and after a week you'll be thinking that you'll never get on with it, but patience and persistence pays off. Mine's like riding an armchair. Other than uphill, it's fairly quick, you notice cold days less because you are not fronting into the cold wind, and you see what's in front and above you, trees, buzzards, aeroplanes - not that bit of tarmac 5m in front of the front wheel.
After last winter I found my Defy to be almost unrideable as a result of neck and shoulder pain, so I'm scavenging the parts I need for my new Performer High Racer (buying a frameset direct from the manufacturer) and consigning the rest of what has been a very good DF bike to the attic - it's recumbent only for me now - other than the shopping hybrid.