Before I purchased my new power wheelchair, possibly a Quickie I wanted to seek some advice from people who already have similar wheelchairs. I've been using Permobil for the last 20 years nearly and they have had front wheel drive. Has anybody switched over to mid-wheel and spider track? If so, do you regret your decision or are you pleased you did so? One thing that puts me off spider track slightly is I think the small wheels could well catch in divots and holes if you are going over rough ground.