A tandem is a great way to travel: you can chat whilst you ride and whats more you only have one set of wheel resistance, one set of wind resistance and 2 sets of pedal power so you can really nip along.
But riding a tandem requires a bit of practise as for the person behind it seems a bit odd that there is no control. However once that has been mastered it is just plain sailing. Also its quite a long distance between the wheels so it has a longer turning circle: not quite so maneuverable although you wouldnt notice that on a road journey.
All in all though everyone should try it .
with that in mind I have built a wooden (what else) tandem
however this bike has a few other useful features: it is electric powered and you can dismantle it for storage or transport