My Current Campaign
My current group consists of heavy power gamers that want heroic, well heroic everything. In the past Ive always used stats rolled 4d6 drop the lowest and usually roll maybe three sets and let them choose which set they use. Usually rerolling ones. That was in the past and works well enough.
Personally I like the 75 point system with a simple one for one basis. It allows my characters to come to the first session with a definite idea of how they are gonna build their character. It also offer equality among players. (With rolled stats, someone is always going to come out ahead, and someone behind as is always the case in chance

) I feel that this equality helps balance more the the realism of randomness does and thus makes for a more fun game.
My group didnt want to use this method though, counting on the chance that they would roll awesome scores. (Apparently their last DM would let them roll sets of stats all day long until they rolled that crazy set of epic stats) So I had them roll the straight 3d6 for 3 groups of stats. Not rerolling ones. Then I allowed them to add 6 points in any way the saw fit.
Now, I thought they would want to round out their stats some, but the fighter saw the oppurtunity for a 21 str and but all the points in that. the rest pretty much followed suit, leaving myt group with one stat 20+ and the rest average, very average :\ This group is always very good at using the rules to their advantage and i expected i had unbalanced the game severely. However they were very excited about their exceptional characters so we continued with some adventures.
A couple adventures later what i realized was that these epic stats only helped marginally. And the characters all had weaknesses which would come into play regularly. Balance had NOT been significantly affected as i had thought.
However, i do fell that balance _is_ significantly affected when i let them roll that supersafe method with rerolled ones or letting them keep rolling sets of stats until they get multiple high scores. when a character has all +modifiers, then they became so well rounded that they are exceptional at any situation.
This whole experience was very haphazard and riddled with mistakes that i made in an effort to save game balance and let them have fun. however i think it did serve to show me that high stats help, but the difference between 18 and 20 is just a +1. The PC with straight 14s would have been much more effective.. but shh dont tell them i said that
Im not so concerned with what method i allow them to roll up stats. i just wonder how often scores above 20 have unbalanced the campaign and likewise how often scores below 10 have unbalanced it.
This is what lead me to the idea of allowing 1 ability point at each level, AS LONG AS THE BEGINNING STATS WERE NOT ALL HIGH (ie not rerolling ones or dropping dice) then the characters will be more concerned with rounding their stats out. this still poses some problems and i could really use the view points of some dms.
my powergamers rarely give any good advice regarding rules adjudication: they are rarely objective and have only experience with one montyhaul dm for a year or so when 3.0 came out. I have played for many years but i havent played since 3.0 came out. So we both come to the table with preconceived ideas of how the game should be played and not much experience with game balance. Hopefully these boards can help me be better at integrating my experience with the new rules and understanding how they are balanced by other dms.
I appreciate your help,
Anony the Mouse