Eh, don't care for it. For one, it's kind of lazy. It's starting with an adult Superman and wanting to explore his youth, but then instead of creating a new, specific villain for young Superboy they just took Superman's main one and brought him into his past. The other reason I don't care for it is it defeats the purpose of Smallville being, well, small. You're saying Earth's two most extraordinary people both happened to come from the same small town in the middle of nowhere? Superman and Lex meeting in Metropolis works because Metropolis is a crossroads. Smallville, IMO, shouldn't be that.
I'll concede that there's value in making it so Superman and Lex have a rivalry going back a long way, but not like this under the modern context.
And don't get me started on stories how young Bruce and Clark Kent were also friends...