My experience so far:
Mostly good. It took around the time that I'd thought it would to download the first 150 GB or so. I downloaded the surround samples during the last 20 hours, with no issues. Installing the last part now. Installation is pretty slow, and I think I see why. I went into CPU Temp, and noticed that the installer is using only one of my four cores even though Process Manager says that the affinity for the installer is set to use all 4. So that's mostly on Toontrack's programming, I think. I did have an issue trying to install directly out of the TT Manager. I was getting a message saying that _____________________.obw couldn't be copied. However, I was able to get around this by launching the installer directly out of Windows Explorer.
I like the features a lot. I'd like to see some improvements made to the grid editor, especially compared to BFD3's, which has articulations and "humanization"/randomization options. I never tried EZD2, but I like the song creator a lot, so that's new to me. RAM usage is a bit out of control when not using the cached mode, but I guess that was to be expected. I have 16 GB ram, and with guitar and bass samples, I can see that maxing out easily. So I can see myself upgrading to 32 GB ram, which I was planning on anyway.
I'm liking the new samples, but I haven't spent an abundance of time tweaking them either, so I'll need to reserve my judgment until I get the full sample set (which is almost done as I speak) installed and I spend more time tweaking/mixing. The new drum sample tuning algorithm sounds FAR more natural, to me at least. I DO like the new effects, but I still see the need to use external processing, either in the box or out.
So far, I think this a good start for a new release but I definitely see areas where improvements are needed.
That said, I despise the fact that TT is charging extra to get the samples pre-installed on a SSD. Especially at that price point for people who are upgrading. But at the same time, I don't know if I'd trust that. When I received the Progressive Foundry thumb drive, it was corrupt upon arrival (plugged it right in, tried to install, and it was all f'd up) and I was forced to download it.