RPG Equipment - Lumping or Splitting?

If there is one thing I like about Rifts, it's the diversity of equipment.

Rival corporations and companies (and in some cases, even weirder stuff) putting out kewl weapons, armor and other equipment that have their own distinctive brands.

A similar feel is in cyberpunk 2020, Darwin's world d20 and I'm sure others can mention a ton of other sources.

however, there is a side effect of this.

Namely a ton of stuff that people just don't use.

In contrast, I was incredibly less then impressed by the 3.0 arms and equipment guide. It really felt like it fell short, especially when compared to the 2nd editions aurora's whole realms catalogue, but it did contain one very key line.

namely that your style of weapon doesn't matter...it could conceivably look like anything within a certain metric, but the stats wouldn't change.

4th edition dnd and especially the new gamma world really take this frame of thought to an extreme (heck gamma world just uses one handed/two-handed and light/heavy and melee/ranged to differentiate between weapons).

My questions are as follows:

1. Do you prefer more or less choices for equipment?

2. what convinces you that something needs to be added, equipment, to a game?

3. If you are a lumper when it comes to equipment, how do you define rival products? Do you simply emphasize the color text or do you do a minor tweak and use it as a definition for the role of a corporation or kingdom?

4. If you split, where do you split and how. Not many people care about 35 pieces of av equipment, but weapons are usually a defining splitting category. 

5. Which genre's or games push towards lumping or splitting?