The 40/2.8 Micro Nikkor punches way above its weight for a <300 buck lens. Seems to be the descendant of the venerable 55/3.5 and an excellent choice for anyone interested in close-up photography who might be initially hesitant to spend more. Hear more tiresome recitations about its working distance limitations than actual experience--the old echo chamber at work again.
The echo is however true.
I've got a Tokina 35mm macro and whilst 5mm is a big difference in angle of view at short focal lengths, the working distance differences are not vast and are comparable. The 35mm is a very fine, very affordable lens that I do like using; but never at 1:1 magnification. In practical terms its close up; if you go closer and all the way to its limit you're so close that you will be shadowing your subject; furthermore the very short working distance means that you've got very little space to get lighting like flashes positioned.
My advice (and I accept that this is an older thread and that the OP might well have made his choice) is that 60mm should be the shortest focal length for macro work at 1:1 for practical intents and purposes and that ideally you want 90mm or longer if you're a beginner.
Working distance = distance from the front of the lens to the subject
Minimum focusing distance = distance from the sensor/film to the subject
Note Working distance tends to only appear in macro because you're close enough that the distance from the lens to the subject is significantly different to the minimum focusing distance; whilst for most other situations the difference between the two is negligible.