Yep Rob - focusing is critical when shooting wide open at f/1.4 and this lens caused me a whole lot of grief when I initially bought it, since my keeper rate hit the floor... you need to be really careful using the D2X with this lens since the AF sensors are so bloody large and can be tricked into locking on to areas with more contrast or detail than your intended target.
The rule of thumb for portraits - 'focus on the eyes' - is the key and what makes the f/1.4 lens so great to use for such subjects; you can get the eyes razor sharp and, because everything else is creamed-out bokeh, you're just continually drawn back to the eyes. None of the other press or agency photographers that I know own or use this lens and, in my opinion, it helps give my images a signature look which hopefully translates into more sales.
If you read around the web there's a wealth of opinion citing the Nikon 85 f/1.4 lens as one of their best ever... equalled and surpassed only by the likes of the 200 f/2, the new 300 f/2.8 and the 400 f/2.8. Considering all of those lenses cost north of £2.5K each (£5K for the 400!!) then thats really saying something.
If you have the means, I'd strongly recommend that you pick up the Canon 85mm f/1.2 lens for your 20D since the results are comparable and worth every penny
