Boonex likes to create a lot of hype when they have a new version that they have been working on. This time around it's DolphinU. I don't see anything wrong with creating some buzz and getting people talking about it. However, they tend to toss it out there before it does much.
By the time it actually matures and becomes usable for a live site much of the buzz and hype has worn off. The only thing I can think of why they put these new versions out so early in the development stage is so they can get others to test it out and find bugs and other problems for them.
On one hand, this is smart because they don't have to spend as much time finding issues themselves. On the other hand, it seems like a complete waste of time to even bother with. I guess if you have nothing better to do, then hey why not?
If you are a developer and you intend to create modules or themes for DolphinU I guess it could be helpful to have a peek at the source code assuming that it doesn't change that much, which I wouldn't count on.
I enjoy Dolphin and seeing what they are doing with it, but it's just not worth my time at this point. I have looked at the online demo on a few occasions, but there isn't much to look at yet.
In my opinion their alpha releases shouldn't even be called alpha. They are more like pre-alpha's (for a lack of a better word), because they don't do much, and a lot of things are broken or don't even work yet. Their betas are more like alphas when compared to other scripts and software. Their RC's (release candidates) are more like beta's, and the first 1-4 stable releases are more like RC's. It's not until a stable version 3-5 ish that it really starts to take shape and begins to be usable in a live environment. This is just my opinion, and based on what I have seen in the past with other versions.
I know people get excited whenever something new is announced, but I don't see what the hurry is. I personally prefer to wait until a very stable and usable version is available rather than jumping into something that is full of bugs that needs to be worked out yet.
The other thing is if we look at how various Boonex releases have progressed in the past it is likely that we will see many alpha, beta, and RC versions as DolphinU matures. If history repeats itself I wouldn't expect to see an usable DolphinU version suitable for a live website for quite some time yet. We don't know that for sure, but at this point it appears unlikely that we will see a solid stable version in the short-term.
So, calm down, take a deep breath. It will come about eventually.
If you are torn between Dolphin 7.1x and DolphinU I would go with version 7.1 if you need something usable soon. Otherwise, if you are not in a hurry, then by all means wait for DolphinU. Just keep in mind that you could be waiting longer than you anticipated.