I knew I wanted to try Smolov, but I have never squatted for high reps and never squatted 4x's a week. I felt Smolov Jr would help be get close to the rep work required for Smolov and get my body used to squatting 4x's over 7 days for 3 weeks. The soreness the first week was "interesting", but after the first week it was replaced by tightness. I had to do a lot of stretching and foam rolling to get loose.
After I went thru Jr and tested, I took a couple of weeks before I started the Intro Phase of Smolov. The Intro Phase was cake compared to Smolov Jr. and IMO, is not really a good prep if you aren't used to squatting with such volume. Smolov is the hardest workout experience I have ever faced. It takes a LOT to get thru it and the guys on this forum help a lot with their support, but you have to have the intestinal fortitude to get thru it cuz it's YOUR thighs that burn, YOUR lungs that feel like they will burst, YOUR hips that dont want to bend.
I would suggest trying Jr and then decide if you want to do regular Smolov. But, keep in mind, Smolov Jr and Smolov are NOT in the same league. But, Jr will show you a little of what it takes to get thru.
Another thing is start a log, no matter which one you do. All of the guys that care and have been thru Smolov before will be there to support you. The reason is, we know how grueling it was and when we read someone else's log, it makes us want to do it again. It's a sickness.