So here's my rundown of Blogger BETA. The labels/tags feature introduced by Blogger BETA was the main reason which drove me to switch to it.
One thing good about this new version of Blogger is that your post is published straight away without having to wait for the timer to finish. And there are finally labels which are really long overdue! Unfortunately, I can't make use of it yet as I do have some problems with the template.
For users who are pretty uncomfortable with hordes and hordes of senseless HTML bombarded at him/her, Blogger BETA now allows them to more around their blog content easily by dragging the appropriate page elements using your mouse and place them wherever you want. It's so easy to customise the default Blogger templates by simply dragging and clicking. And you can also add like your Javascript clock, links, archives etc. (those sidebars widgets) into your sidebar very easily.
Unfortunately for amateur HTML tweakers like me, editing the HTML codings are terribly difficult. I have been faithfully using HTML the whole while and suddenly, I have to switch the programming language of my blog to XHTML and XML! I was clueless as to how to tweak my current layout to adapt BETA's new compabilities, because first of all, I have zilch knowledge of those two web programming languages. And that means having to learn everything from scratch once again. And I dread doing that, seriously. It's very time-consuming!
Thank goodness there isn't much to learn for XHTML as it is pretty similar to HTML with a few obvious differences that I can easily adapt to in a relatively short time. Like for instance, the tag elements must be all in lowercase (I have always written them in uppercase). This in my opinion makes tweaking the codings more difficult for me as I cannot really differentiate quickly the tags and the normal text contents.
Hmm, I wonder why Blogger calls it 'Edit HTML'?

And Blogger BETA's default templates is really straining my eyes when I try to refer to them as examples. Everything, or rather most part of the codes are all clustered up together and I have to try and find the end of a particular piece of code and create line breaks just to separate them from the others (it's easier to edit that way).

And Blogger Help wasn't of much help too, especially this piece of article which teaches me how to properly code the widgets code. It's so frustrating trying to make heads or tails of it, and I was really confused after reading that. And the default templates seem to have complicated things.
Why must there be so many new Blogger-specific tags? I don't get it, the old one was so much better and less complicated to do. But this new one makes use of XML, and not only that, it's pretty confusing too.
And that is why I have reverted back to using the classic template instead of the new one. I simply am really clueless to do anything at all. I even spent the whole day yesterday trying to figure out where to put such codings, with no luck. Blogger BETA kept telling me "My XML file is invalid", therefore my template cannot be even previewed at all! Sigh, why bother... I think I am stuck with this for the time being. And probably read up more later.
Overall, I have a pretty sour experience with this new interface of BETA, which spoils the whole image of everything. So should you change to Blogger BETA?
Yes, if you are uncomfortable with HTML and you prefer working with GUIs, then Blogger BETA is for you! It cuts down on your frustrations and confusions by hundreds of percents. If, on the other hand, you are familiar with XHTML and XML, then I'm sure you can quickly implement and harness the new lucrative features offered by Blogger BETA into your blog.
No, if you are like me who dislikes the rigidity of Page Elements and you prefer working with your layout directly. Unfortunately, the whole editing layout thing would further frustrate you if you are foreign to the terms XHTML and XML and you have absolutely no clue on how to tweak your template. I also heard that BETA blogs suffer glitches too, especially the comments, but they should hopefully be quickly resolved.
Other than these, there aren't many noticeable changes in this new version of Blogger.
P.S. This review is written by a HTML purist, who has recently discovered the wonders of XHTML, and he is slowly adapting to it. This review is also focusing on the new template aspects of Blogger BETA. This might be inapplicable to you if you do not bother much about layouts, and if you are so, I suggest you switch to Blogger BETA just to take advantage of the new labels feature.
[+] There's more!