Indeed, but Stronglifts recommends low bar so I'd be doing the wrong exercise for 11 weeks.
Didn't mean to knock the high bar!
/dons flame suit
I am actually impressed by how full of rubbish the Stringlifts guide to squatting actually is, particularly for a routine based on squatting. Having survived reading it and losing 10% of my paltry gains in the process, it actually talks about high bar... But whatever.
Does that make me weak back but strong legs?! Would make some sense
Not necessarily... It was actually an unfair jibe at Mr. Stu as I am being judgmental as to his squat technique: a lot of people are tempted to completely forget what the hips are doing in a low bar squat and good morning the weight, instead.
Sorry, Mr. Stu... However, you are still misguided.
What's difference between low/high squats in regards to leg/ass/back development?
Think i've been doing high on SL so far, just felt like a natural position
Depending on how you high bar squat, there can be quite a significant difference in muscle activation and - as a result - strength/size development. Typically, low bar is more posterior chain dominant, with high bar being more quad dominant.
Both will ruin your wardrobe where trousers are concerned (glutez kick in above parallel for both), and both stress the back in slightly different ways (core has to be mighty strong for low bar due to the less vertical torso). Ultimately, the decision for one or the other is normally a result of training objectives and potentially limb length/skeletal structure, because the shortcomings of either - in very general training terms - can be plugged with basic programming (high bar + RDLs; low bar + front/split squats).
For specific training outcomes, however, certain styles are preferable due to similarities with the sport being considered. For all-round development, neither are a problem, but both need assistance work to make up for their (tiny) shortcomings.
But high bar is better.
You are simply efficient and balanced. 
Weak shoulder of weak.