Mixed orthography is very popular today, and slowly becomes de-facto standard in Israel (although I personally think it's a little bit controversal.) The idea is to show Hebrew words written with exactly the same letters, regardless of using vocalization or not. Actually, this is the way many Israelis would "intuitively" vocalize the Hebrew words: first write it the usualy way like they are written in כתיב מלא and then add some minimalistic vocalization.

Consider the following words:

As you can see, the idea is simple: we take a word as it would be written in non-vocalized orthography, and add the nikkud to make it "sound" correctly. (The only Schwa we want to write here, are the Schwa which are actually pronounced today.) It seems like something a natural for native language speaker, but in reality native speakers are not used to use the Nikkud at all.

The main advantage of the mixed orthography for Hebrew students is that they only need to learn one spelling. It looks Ok for those who just needs to learn Hebrew good enough to survive in Israel (and I have to admit, 90% of Israelis are Ok with this level of knowledge.)

The disadvantage (in my opinion) is, that with the mixed orthography some aspects of Hebrew grammar are hidden from the student. Hence there is no difference anymore between Kholam Maleh, Kholam Khaser, and Kamatz Katan, the syllable structure is broken, the number of "exceptions" is growing, conjugation of verbs and nouns in Biblical Hebrew becomes a mystery: the orthography looks "strange" and "obsolete". Sometimes, for a student who is used to the mixed orthography, reading a classicaly vocalized text gives a strange feeling...

Example:

Why in the word צָהוֹב when you put it in feminine form (צְהוּבָּה) the Kholam is changing to Kubbutz, and in the word גדוֹלָה the Kholam stays there, as in גָדוֹל?

Typical Ulpan teacher will tell you something like "ככה זה" ("Just because"), or will mention some "complicated rules" which she probably doesn't remember herself. In the best case, she will say, that those two words are built with different patterns (משקלים) - which is true, but it's only part of the truth. However, the truth would become obvious if we knew that in the word צָהוֹב the Kholam is actually Kholam Khaser: Kholam Maleh (as in גָדוֹל) is never changing, not with a word transformations, neither when a stress is shifting. At the same time, Kholam Khaser is changing either into schwa or into a short vowel (Kubutz or Kamatz Katan) - in fact, that's why the Masoretes wrote it as Khaser, because it tends to change.

The thing is, you always can go from the classic orthography to the mixed, but not vice versa. Therefore, I would recommend (if you have enough time and passion) to invest some effort into the classic orthography (and classic grammar as well), then the transition to the mixed one will be easy. In fact, you even won't need the "mixed orthography" then: you will be using the non-vocalized orthography (כתיב מלא) as most Israelis do on everyday basis, but your knowledge will be based on the real Hebrew grammar, rather than on a "quick surrogate".

From the other hand, few people would like to add an extra "layer" to their studies. Even fewer would agree to dig into ancient history trying to understand "theoretical pra-Semitic form" of a word, something like מַלְכּ or צָהֻבּ. Apparently, the main reason behind the new orthography (which eventually will imply new grammar) is because the traditional orthography simply becomes impractical.

What you want to learn will solely depend on your practical needs. I have to admit, that you can perfectly survive with the mixed orthography; moreover, the whole modern Hebrew is evolving in this direction: vocalization is almost not being taught in schools anymore, although educated people of the "old school" will probably know the classic vocalization rules. Is that problem of Israeli education system, are there any political reasons behind it, or is it just the natural way of things? I don't really know. I see my mission in presenting to my readers all the aspects of Hebrew, both classic and modern, and that's what I'm trying to do here.

Thanks for reading this article,

!תודה ולהתראות

Later addition:

According to Wikipedia, Even-Shosan dictionary (the most "official" Israeli dictionary) started using the Mixed orthography in 2004. Like it or not, this is a point of no return.