It is a well thought out pen design. Very comfortable in my hand, and easy to take apart.
If you want to completely take it apart, you can, but be careful with the piston mechanism. I marred the threading on mine, and now the twist when plunging is stiffer and toothy.
If you want to buy one used, try to get one with a solid metal section / nib hood / grip. Like I said above, the older design for this part is the biggest complaint I have with my pen. The seam between the plastic and the metal is where my fingers sometimes go during writing, and ink would slowly seeps through and stains me. What I'm talking about here is, when you flip the pen over and look and the under side of the nib, the plastic U shape where the nib meets the pen. Not where the metal section joins with the fiberglass body.
The 2000 is prone to 'burping' ink into the cap due to temperature changes. Often times it will need a wipe after uncapping.
The fiberglass body is a really nice experience. It feels 'warm' or like an organic material to the touch. Similar to a textured wood.
My nib was a dry writer when I got it. I spread the tines to make it much wetter, but it wasn't bad out of the box. The 2000's nib is different (smaller) than the rest of Lamy's line. There is one compatible pen from their history, the Lamy 27. The 27 had some nib grinds available that the modern 2000 doesn't have. I've often thought about swapping out my Medium nib with an Oblique Double Broad from a 27.
It's a semi-hooded nib, so it does ...ok... if you leave it uncapped on the desk for a while. You'll find you can take a moment's pause with having problems with dry out. If that pause becomes a pondering rest, though, you should probably recap it.
The nib feels soft and supple, but not springy when writing.
My pen is 7 3/4 years old. The body is free from scratches or signs of abuse. It looks like it did when I got it.
Writing reviews isn't a strong suite of mine. If you'd like to hear something about it in specific, let me know.
There is an interesting post about the design of the pen on FPN