I've built a couple of these. They're ok, but aren't the most accurate, but still quick and fun builds. The Eduard set is a must and really improves the finished product.
Eastern Express doesn't do a BT-5, but they do the whole BT-7 series, which is more accurate and more detailed-especially with the Eduard sets for those kits. Unfortunately, I bought all of the EE BT-7s right before Tamiya released their BT-7, which is very nice, but a lot pricier.
I've built a Tamiya one now, but will build one or two of the EEs in my stash and probably sell the rest cheap as I've built the Tamiya version(s) now!
I love the early war Soviet stuff, so I'll be following this one for sure.