No worries. I think we're pretty much on the same side of this particular argument.
That was raised by multiple posters upthread. The only reply I recall was from @
Johnny3D3D , who (pretty reasonably, I think) gave it as a reason for preferring the GURPS 3d6.
I did, but it is important (to me) to note that I still like some amount of randomness. I only mention that because I remember a few early 4E talks which had considered ditching die rolls completely. What I like about the bell curve created by multiple dice is that it produces more-or-less consistent results, but consistent doesn't necessarily mean predictable.
I have a really easy example to illustrate why I started to like the bell curve:
Back during the twighlight of 3rd Edition; when 4th Edition was just starting to bud into a twinkle in the eye of WoTC, there were many heated conversations concerning why critical fails on a 1 were a bad rule. There was one argument in particular which struck me, and that was that a high level fighter in 3rd Edition had a higher chance of critically failing than a low-level fighter by virtue of needing to make more rolls on a d20 for a full attack. For any given roll on a d20, there is a 5% chance to roll a particular number. With multiple attacks still using only a single d20 roll for each attack roll, that meant that -with each round- a high level fighter had multiple chances of rolling a 1 in contrast to a level one fighter only having one roll.
Now, switch this over to GURPS with 3d6. The average roll of 3d6 is still 10.5. However, with multiple dice, the results of a roll are more likely to be somewhere around that average value. This means that if I have a 'high level' (GURPS does not have levels) fighter who has a sword skill of 16, he will more consistently roll under that number in contrast to someone with a skill of 11 or 12. (Note also: GURPS is a roll under system.) When my fighter character becomes more skilled, that does not also mean he somehow has a higher chance of stabbing himself or befalling some other critically-bad fate. I'm away from my books at the moment, so I forget the exact % chance of rolling each number,
So, what about those criticals? Normally, a critical success in GURPS is a roll of 3 or 4; a criticall failure is a roll of 17 or 18. (If that seems odd, remember, it is a roll-under system.) However, here too there is a rule which makes skill matter. A roll of 10 less than my effective skill is treated as a critical success. Remember my high level fighter with the skill of 16? I can critical by rolling 6 or less. (This rule caps out at 6 though, so someone with a skill of 17 would still need 6 or better to crit.) Also, since my skill is so high, critical failure only happens on an 18 now instead of 17 and 18. Between this and the bell curve, I get a better sense that leveling up means getting better instead of the 3rd Edition model in which being a high level fighter also means I have an increased chance of critical failure.