Let me first disclaim my following statements by saying they are mostly my opinion.
Some techniques are improved with strength, some are not, some are hindered by one's amount of muscle. Technique is a good deal of a match, but size and strength can help. Strength moreso though, i believe. One thing that i have always been told in sinking a choke is that "if you have to use any strength, you are doing it incorrectly" To the end i believe this is correct. But where strength comes into play is keeping one at bay while a set technique is performed. If your legs are weak it is hard to keep an opponent form passing guard and gaining the mount. No matter how strong you are in a situation when someone has your hips (through either luck or good technique) you are screwed. Strength is a benefit always, size is not. Use everything to add to your technique, not replace it.
Some comments in this thread have been purely derogatory and who cares with the name dropping "this competitor does this and..." Who cares. Stick to facts and your opinions, do not de-rail others opinions on account of personal differences, just argue them accordingly.
To summarize:
Gear does give an advantage, but only if your training is allready well-rounded. As with everything, build a foundation (technique) and then follow with all else. If someone can beat you with little contes regularly then aas usage willl probably not help; but if your training is good and a opponents is equally as good and you guys usually have very competitive fights, then this is where maybe a little added strength will come into play. AAS is not THE answer it is A possible supplement to the answer.
Just my two cents.