How Good is Denman as a racehorse? Could we even begin to compare him with the mighty Arkle.?

Arkle remains as a legend. Great racehorses don't come too often. Even very good ones are rare: Desert Orchid; Burrough Hill Lad; Carvill's Hill; Best Mate and now Denman. His performance in the Hennessy was something very special and if you are young enough you might see something similar in twenty years time. So can we compare him with the mighty one - Arkle?