The Vertical card has become the popular choice for some reason and could be a bit confusing for the student or low timer to orientate themselves with this type of compass, I have seen some have problems with orientation of the DG when just new to the game!!
As a student... give me the card compass every time - it tells you where 'East' is when you're flying North. I've flown two R22s into EGBK and they both had card compasses, thankfully. I hope I haven't made the east/west mistake on calls...
One thing - Sywell is an unusual field in that the pattern made by its runways doesn't really align with a cardinal direction. In fact they make an equilateral triangle pointing in 'no particular direction' which makes it a little harder to visually overlay cardinal points on the plan view of the field.
Am I making sense?
Benet
Edit:
http://www.sywellaerodrome.co.uk/home.html