Ron Garcia Super easy and fast build. It only took me a few days from start to finish. Having link and length tracks certainly helped. Both sides of my tracks were a tight fit so there isn't much of a sag, if any, to them.
The only issue I had was with the PE grating on parts E5 andE8. All three PE pieces for each were a little tricky to attach (at least for me) because of confusion caused by an outer edge and an inner lip for all three areas they attach to. Even though the instructions show each should be attached to the outer edge, the inner lip seemed logical for a couple of the pieces. I'm not even sure why there is an inner lip in the first place! After the first one was completed, the second was a bit easier.
The above confusion by me notwithstanding, this kit is an easy recommend from me. Having now finished the BT-2, BT-5 and BT-7, it's interesting to see the them sitting next to each other and see how this series of tanks' designs evolved.