The Bladerf is very easy to use. Good documentation. Pre-built binaries for the firmware and PC side APIs. I've used the C API extensively on Windows. Unfortunately as with pretty much all SDRs, the RF performance is pretty bad (spurious/images/etc). IIRC it has some odd limitations on the anti-aliasing filter and was quite CPU hungry at higher tx rates. You're not going to find an SDR without quirks though.

Better SDR gear is out there for a price: https://www.ettus.com/product/category/USRP-Bus-Series (these are their cheapest models)

I haven't worked with it so I honestly can't say.