a) were incredibly OP, especially if their design flaw, which unintentionally allowed for stacking of several layers, was abused. Endless resources at the cost of cheap energy. The only reason you'd ever switch off one of the old farms was because you couldn't be bothered to deal with the deluge of resources they swamped you with. It just wasn't fun playing with them for me. I haven't built one of these things in a long, long time. I went out of my way not to build any in my legit worlds.
Well one person's OP is another person's happy toy I suppose. Since you're writing it I can see the desire to change it. Mean if you won't use what you wrote then why invest the time maintaining it. So from that perspective I understand your point. I'm not so bothered that you changed it, I'm just not really getting the 'feel' of 'yeah now this is what I want to build' from it. Honestly if it hadn't been a hulking monolith that then builds an odd shaped area around it I'd probably not even be in the thread. Something like say the water tanks where you build the outer parameter up to a certain size in say a square with a cross brace in the middle so it all connects. Even if it required X air blocks over it. Same blocks, different pattern.
The fact that you did away with the humus requirement and let the fertilizer handle it really soothes my issue of supplying it. While I can't create the apatite from thin air in a closed system I can get enough of it from quarrying a mystcraft world or 3 to run for mathematically years of real time.
b) were dead, deeply flawed code. It hadn't been touched substantially in something like six months and it showed. Everything was creaking and little things were breaking. Dirty hacks to patch things up all around. And they still cracked at some points (Arboretums going haywire with rubber trees anyone? Fixed height for all trees, making it impossible to harvest larger trees, etc.)
This I can really sympathize with. I end up dealing with a lot of code in my professional work and you can only band-aid stuff for so long before it takes up all the time resources just to keep patching it than to progress. No doubt it definitely needed re-doing. We all tend to learn new stuff over time as well so I imagine it shows considerable improvements given the amount of code work you've done and no doubt learned from.
c) felt flimsy and cheap. I like magic blocks as much as the next guy, but after a year, a single, brightly colored, cartoonish looking block which harvests melons 5 blocks out and 5 blocks above just felt wrong, almost comical. I don't want to knock the old farms too much, I had a lot of fun playing with them for quite a while, but they used up all their novelty to the point where suspension of disbelief just wasn't there anymore. Granted, the new farms can still be said to be a gigant magic block, but I am more inclined to believe, that these large structures house all that heavy machinery necessary to harvest and plant a variety of crops. Imagine a harvesting arm extending outward and circling the central structure while it works and it doesn't even feel magic anymore. (That was actually the plan at some point, but was discarded in favour of making layer placement more flexible.)
Well honestly minecraft is a bunch of magic blocks and magic activity in the name of building stuff. Mean have you ever tried to carry 64 1 meter cubed chunks of rock? I'm not sure I could really manage one honestly. So having a block that auto harvests... well on my suspension of disbelief scale it ranks pretty easy to ignore when paired with everything else. I can see however why you'd feel better about the form you chose and hey it is your mod so code as you wish.
As I think I mentioned I just wish the overall shape had been different with better space utilization. Redesigning buildings and such isn't bad but making them work with everything else just once in while gets to me. Everyone is creating these large multi-block monoliths and the aesthetics of it is falling to the wayside. I've got steam tanks, liquid tanks, turbines, fusion reactors with their coils, nuke plants and many other things that dictate exactly how many blocks x/y/z and tubes of various sorts running all over the place making them all fit properly gets to be a mess unless you just go for the infinite sprawl kind of base.
I almost feel like everyone suddenly watched Space Oddessy or something and got enthralled by the monolith. Once you get too many of them running around it gets painful in the design and planning phase. I suppose it can just be considered a challenge to overcome but forgive me if I express some resignation and lack of enthusiasm for having a system that was functioning just fine, could be hidden and otherwise taken care of easily replaced a bit suddenly from my perspective and in a manner that won't even fit properly in the areas I've built. I'll probably just start my base over, and while I know that is a daily thing for some folks my bases tend to be a tad larger than normal since I take great pains to port them as maps have to be regenerated and versions change.
There is more, but I already wrote way too much anyway. X)
tl;dr: I know some people like the old farms. I will try to keep them around as an option for a while, possibly even longer as a seperate module. I will not guarantee porting them forever and ever. Try the new farms before you knock them. Yes, they take space. Yes, balancing and development is in progress. The old farms were actively developed for almost a year. The new farms have been in development less than a month and under actual public scrutiny for a week. No, I will not try to compete with Steve Cart's tree farms or TC3 golems. (A multifarm doesn't stand a chance against the cuteness of a TC3 golem anyway.)
I do appreciate that you've not hard swapped them immediately. That is tremendously helpful, especially while they are still being fine tuned. In the end nobody can assume that any particular method will be around forever and ever so some change is always needed. I'm definitely going to keep an eye on them as you develop them and I'll probably use them at least some. Each mod brings its own aspects to the table and strengths and weaknesses (TC3 golems are cute, right up until you need 60+ of them in a relatively small area to manage the wheat crops alone). Who knows, in a while I may have a great idea on how to compensate for having another alien monolith in the middle of my fields and write off the odd shaped building as what happens when you outsource to undocumented aliens from space.