Mixed bag for me. I do like the new models. For the last few years the standard of the models has gone up and up. Partially due to competition and also just natural standard increasing over time.
What I am not a fan of is various forms of 'player tax' that seems to have been brought in. I do understand that GW needs to make money, but buying a codex is ok, but then having to buy the supplement codex to get the most out of the codex you bought is not. Dataslates are a funny one. I dislike them bringing out the Dataslates as stand alone products (such as Cypher or Be'lakor) especially when the Dataslate is an incredibly powerful or must have unit (Normal Helbrutes Vs Dataslate Helbrutes being a good example). Forgeworld stuff can also be a pain, but you get charged a lot for the models in that one as well as the books. What I don't like with them is the continual reprinting of the same rules over several books. So Imperial Armour Apoc had a load of Chaosy stuff in. But IA:13 had all of them, mostly unchanged then added in Renegades and Heretics and a couple of chaos versions of imperial 30k tanks (what imperial players had access to for ages)
HOWEVER they seem to be turning a corner with that type of thing and releasing the new units / models as rules included in your purchase or featuring them in White Dwarf (or both). The only prob I see with that is if it comes in WD only and you are a player who started the army long after the WD rules print, so have no way of getting the additional rules for something that could be incredibly useful. An example of this used to be GamesDay Models, where you could only buy the model on the day and your programme had the rules for him. Ones like Crom the Conqueror were insanely good if I remember right.
I do like the Digital copies of the codexes. This helps a lot with travel and stuff, especially if you are going with CSM with Daemon allies and some Forgeworld tanks or whatever. Adding about 1KG in weight with some books it all mounts up if you aren't driving. Also the feature to search for things from a side menu rather than trying to mark up pages is a bonus.
HOWEVER I do not like the format of the recent codexes. Having the compiled list at the end that had all the models in brief with their pts values and the names of what rules affected them was great. The new one forces you to either use something like Battlescribe or endlessly flick back and forth in the book when planning an army. I much preferred being able to see all the units that classed as X over the space of 2-3 pages. Though I do understand in part why GW did it. Some of the reason I have been told was because of copy write law. In that for publications for gaming and hobbies you are allowed to photocopy (or digitise) X% of a book for personal use (X depending on country). Because of this people used to copy the last 20pages of so what had all the stats and costs of each of the units, and then the reference at the end tended to have most of the special rules and weapons. GW of course didn't like this because people could bring in those 20pages with them without really needing to have bought a copy of the book (but claiming they had).
The one big thing I am hoping for though is that currently they have a fast release system on the codexes (about 1 a month maybe 1 every 2 plus a supplement), and what I don't want to happen is that in 10months time when they have released every 5-6th edition book left to bring up to 7th that they then start again and release 7th editions after only having 7th edition out for just over a year.
The other one what might be interesting and soon, is will old supplement books work with new released codexes. So for instance Black Legion and Crimson Slaughter are designed for the 5th edition CSM book. But will they still work with 7th edition (what I think is due for april->july next year).