Haivng played at least a dozen (only 3 being WoD)...
if you're going count successes, WoD's method (explode on 10 if skilled, granting an extra die) seems pretty easy.
Playtesting the current Robotech (we dropped out), all of my players hated the dice mechanic, where 2×4's equaled a success, 1×5 was a success, and a 6 was 2 successes. I don't know if that continued on into release. They flat out said "No more" when they found out that modifiers could make 4's a full success and 5's two, or make 4's nothing, 5's half, and 6's 1 success... THey didn't like 4 result states, let alone modifying those. It also didn't come to intutiveness.
excepting symbolic pools (FFG, proper Modiphius effect dice), having more than 3 states for a die is way too many, unless some of them are pretty mnemonic...
FFG's effect dice are sufficiently mnemonic for me
1-2 result points = roll
5 and 6 are 1 and a special
mediocre dice (3-4) get nothing.
My favorite count success d6 dicepool is that of Arrowflight 1e. stat dice, rolling for skill or less. if 3 or more are 1's, roll another full pool's worth and add. If more than half the dice roll 6's, and the action fails, it's a fumble. Difficulties modify skill; when the TN goes over 5, the TN stays 5, but the difference from counted and 5 is a number of bonus successes gained as long as at least one non-6 is rolled.
The att range is roughly 2-6 with occasional 7s or 8's, skills start 0-4, no unskilled penalty. It's also not available in PDF... 2E uses a 2d6< (Stat+skill) with the same att and skill ranges...