You do what you want to do. But regarding my progress being something extraordinary - It certainly is not. Several months ago I started a thread on startingstrength.com asking for those who finished SS the way it is supposed to be done (utilizing 3 x 5 for squats, eating enough etc.) to post their final numbers. If you look at the answers in that thread and exclude those who got injured for some reasons (or have been injured already when they started the program using it as "rehab") you are getting a pretty consistent picture of guys finishing the linear progression typically between 300 lbs and > 400 lbs
for sets of 5.
Rippetoe himself says that 325 lbs for 3 x 5 after 6 months is typical for a young male that started as a complete novice, meaning that lay-offs, small injuries, resets, canceled work-outs due to other obligations are already calculated in. So under optimal conditions more is possible. I finished at 402 lbs x 5 x 3 - a little higher than Rippetoe's norm - but if you take into account the correct reference population (male, 5'10, early 20s, competitive athlete in a non-weightlifting sport) this is probably rather usual. In that thread I talked about there were several guys who got a lot stronger than me purely on 3 x 5 squats 3 times per week. Here is the link:
http://startingstrength.com/resources/forum/showthread.php?t=17900Again, you do what you like to do and 5 x 5 will probably work fine if you do that once a week and squat at least another time during the week with a different volume and intensity (lower volume for sure, but I am not sure what intensity would work best in your scenario). But that approach is not as efficient and I doubt that you will get more hypertrophy this way. That is because hypertrophy follows strength and you will get stronger faster with 3 x 5 until you are not a novice anymore. Period.