Probably not what you want to hear but I think you need to try the DK out and see if you prefer it to the paladin.

All the tanking classes in the game are very capable and so it is more an issue of personal preference.

I love tanking on my Feral druid for my higher level multibox team (if I ever get it going), however I've really, really enjoyed having a paladin tanking
for my shaman. Aggro is never an issue and the team can go all out instantly. It's even got me thinking about respeccing my bear tank as cat and
swapping the paladin to Prot (but I'd need a new set of gear on the pally).