Hi,
Been there once or twice and always been disappointed with the stock they have and reserve prices, sometimes almost nothing sells.
If you're looking for a quality van auction try Manheim at Dursley, near Gloucester. We've bought a couple of ex-lease vans from there over the years. You can view all the stock online. Stock there usually goes for between £1,500-£3,000 below book value in my experience. And almost all stock sells.
Cheers,
Huw