I have no direct experience with them as I've never purchased one of their products before, so take my comments with a grain of salt. I did the exact same thing you're doing and did a little research. Blueprint engines used to be called another company (can't recall at this time) and they had generally poor reviews. All you usually hear about online though is bad reviews for the most part. On a good note, I didn't find a ton of comments regarding their engines, which I sort of consider a good thing. If someone is really terrible, I usually have no problem finding a TON of forum comments saying to stay away.
I didn't want a complete turn-key engine myself. I went through a vendor I found online called enginesdirect. Enginesdirect.com I believe. They were fantastic. I got a '68 302 long block shipped to my door in VA for $1399+$100 core charge. $1499 TOTAL, and that included return shipping on my core also. I put my intake, carb, and accessories on that I pulled from my 289, dropped in my dizzy, and she cranked right over in the first 10 seconds. I set the timing, tuned the carb, and haven't had an issue with the motor since. That was only 850 miles ago, but I couldn't be happier.
They include a 3 year/100000 mile warranty, they guy has sold thousands of SBF's with 100% feedback, it only took them 4 business days to get me my motor, and I got a real English speaking person on the line every time I called. In fact, the guy's name is Steve, and he was the one who answered every time. I called once to ask questions, once to place the order, and once to call for the truck to get my core return.
My car is a daily driver. I only wanted something reliable and didn't care much for performance. I don't expect to find quality race parts in my motor, not for that price. Your mileage may vary. If you want a performance motor with all high-quality name brand parts, then you're probably better off going with a local builder. Since you mentioned you were looking at a Blueprint engine, I offered you up my experience with enginesdirect.com.
1966 Mustang Coupe