Well so far I must admit this season has pretty much ROCKED for me personally, I have LOVED it! Will elaborate further later!

It is the worse of the three seasons. But in contrast has 2 or 3 episodes that are on the top 10 episodes of the whole show. It's so random... characters come in and out without purpose and there are not straight plots. The fact that Betty is regressing and selfish doesn't help. And other characters that were strenghten on season 2 (Marc, Amanda, Christina... are weakened in this season).
That, and the fact that there's barely no Gio (for the Getties) and no Henry (for the Benries) makes it even worse... and that Horta is also killing the Detty database. I wonder what's their strategy... really makes me wonder.
Good things are the progress of Willy (the Connor story was really good.. though I don't know why they had to neutralize her "evil ways"), sometimes of Daniel (I don't like how they screwed the DJ father/son story but Molly-Daniel romance, though bland, was "okay"). I still don't know why they created Jesse and why Matt is so insipid and still is one of Horta's favorite... but love interest this season are really unnapealing. No romance at all.
The YETI story was amazing (big big plus this season) but they didn't develop it enough and the episodes on the YETI program are scattered. Marc is definitely one of the best characters this season, but they don't give enough interaction with Amanda (why they made them live together in an apartment if they were rarely going to use that setting? In fact, why did Betty move on her own anyway?) It's like they are testing new plots and abandoning it the next few episodes.
I hope season 4 gets better.
Edit: And the music! what is happening to the music? In the earlier season 3 episodes they were using a good season 1-2 style soundtrack... now the scenes sound empty. :-(