Difference between mechanical and electrical coin unit

[OneShot]

Hey guys,

I know that there are some topics about coin mechanisms already on this board, but I would appreciate if someone can sum up very clearly what the differences between a mechanical and an electrical coin unit/validator are?

Till now I think its like:

Mechanical:
- Can only detect 1 certain coin
- Cheap
- Very easy to implement?
- No electricity needed to operate this unit

Electrical:
- Can detect multiple coins
- More expensive
- Needs 12V DC electricity
- Needs more wires to make it work? (= more difficult to implement)
- More reliable than mechanical unit?

I think that the mechanical unit is just like a switch, which connects the 2 wires of my hacked keyboard to generate a pulse so DWJukebox adds a credit.

I think that the electrical unit needs as much wires as it can detect different coins. Each wire will work like above mechanical unit. But because the electrical unit is operating at 12V and the keyboard operates at 5V, a relay is needed to compensate for this.

Does someone have clear pictures about the wiring of the 2 devices (photos and / or drawings). Particularly I am interested if installing an electronical coin validator is much more difficult than installing a mechanical coin validator

My coin mechanism only needs to accept 0.20 euro coins, so if it is much easier to implement a mechanical coin unit, I want to do that.

[edit] If I am buying one of these coin validators, how do I know that they will work before I buy them? I don't want to spend money on something that doesn't work [/edit]