Some people have done very well on it. I've read the doc and I'm not in agreement with a lot of their theory but the program itself can work. Where I would be worried is, what level are the people at that are getting good results? It's a cookie cutter so how applicable is that static program to someone like yourself? It's a paramount issue. The Smolov is a great program for the squat but it will crush most every BBer - does that mean it sucks, no, just that there is an application problem and the people can't handle that kind of volume. Linear programs work great too, does that mean an elite lifter is going to build up for 4 weeks and string together a bunch of PRs? Hell no.
This stuff isn't black and white. If you want to try it, try it - but as long as a program and a lifter aren't totally stupid, the success of the combination will depend upon fit. And I have little way of knowing where you may or may not fit.
I'll also say that the "5x5 program" are not programs, they are examples and snapshots of what training might look like for a given person at a given point in time. I tell people not to screw with them because most people are retarded and need to run it once to see that it does work otherwise they add all kinds of shit and turn it into a 3 day split - basically neutering it back to their usual garbage. The lifter is constantly progressing and evolving, and his training should match that and be altered and changed as needed. The further you go the less cookie cutters will apply for you - why? Because they are made for the least common denominator (i.e. Joe Bob at 24 Hour Fitness) and the further you move from Joe Bob, the less likely generic 'for everyone' programs will work for you.