I don't know which bike you are referring to as a BSO. But mine is a Magna that came from Target and I grabbed second hand basically for just taking it away. I used to only ride big box bikes (except for my bmx) until about 2 years ago when I got my first real bike. An entry level Japanese built Kuwahara Newport Road bike sold in Canada. I still love the big box, BSO, what ever you want to call them bikes. For riding slow paces, short (no more than 10 miles so far) distances with the family they're great. I can get 2 of those bikes and clean/lube them for less than what one tire costs for my road bike.
Is a bike equipped stock with tiagra or 105 a BSO? Really hate that term.