Having owned a vintage 808 for years and currently using an OCD I don't think these two pedals are actually competing in exactly the same category of effect. Sure, they are both distortion devices but the 808 has much more of a mid-range focus great for single note lead lines whereas the OCD has a more flat neutral midrange aspect to it. Think of the OCD as a Brit crunch channel great for chords and riffs and the 808 as your third lead channel for single note lines.

In other words, get both ;-)