I know that this has been mentioned in other places, but I thought I might try and condense some of my thinking (and perhaps the thoughts of others) in this thread. As others have mentioned, the Logos app becomes nothing more than a glorified e-book reader when you go offline. It may be great to have access to all of my books when I am online, but unless you have downloaded all of the resources (which is a tedious task in and of itself) or are online, you are extremely limited in what you can do.
We really need there to be greater offline capability on the iPhone and the iPad. If not the iPhone, definitely the iPad. Here are some of my thoughts as to why it is essential.
- 3G is slow at times and unreliable at others. To rely on either AT&T or Verizon (or another carrier via a hotspot) is to cripple the app. What if I am preaching in an area with basically no 3G coverage? What if the network goes down? I have had both of these happen to me.
- WiFi, like 3G, is not always available. I have an almost 8 week old baby. The other day we stopped in a parking lot while out so that my wife could climb in the back and feed the baby. Guess what--no WiFi in the middle of the parking lot! This is just one instance of many where I was wishing I could do more but without WiFi, I was unable.
- Missionaries. Many are in places without consistent access, but could use the portability of Logos on the iPad.
- Money. I have an iPhone so I could use the hotspot feature to always have 3G access, but at the minimum cost of $20/month (Verizon). For those of us laboring with smaller churches or trying to get through school, that is a lot of money on top of our what may be another data plan. I would like to make the investment in the iPad as it is a great ministry tool. But an additional fee on a monthly basis to be able to use Logos in its entirety is hard to swallow.
- Accordance. Their iOS app is, in many ways, far superior to the Logos app. When we have notes and highlighting, that will catch Logos up. But their app's baked in capabilities are fully functional offline.
- Logos. I have come to expect the best out of Logos. I appreciate the functions that I have now, but I really believe Logos has only began to touch the mobile capability of iOS.
So what would I like to see:
- The ability to choose to download all of my resources. I know that this is a lot of information, but you could force the app to do it over WiFi once and then have all of the resources. Once downloaded, you would be free from the bonds of 3G and WiFi. I also know that it will take up a lot of space, but that is space I believe many would be willing to sacrifice for full Logos usage. I wouldn't mind having fewer songs, videos, etc. with me. Even if full offline use was not immediately available (since it will require coding, testing, etc.), this seems like a feature that would be simple enough to place in an upcoming update.
- The ability to do word studies and the like offline. It has been commented that the iPad is not a laptop and should not be expected to function as such. That is true. But the iPad and other tablets are becoming the go-between so that one can have something more compact than anything else out there (even the MacBook Air) and still be able to be productive no matter where you are. The iPad/iPhone has the processing power to handle a scaled back version of the Word Study, etc. I don't fully expect complete desktop capability, but a scaled back version would be at least a start.
- Of course, I would love the notes and highlighting to be available and able to sync, whether I am online or offline. If I were not online, I could highlight and take notes that would be synced the next time I went online. (I have read notes and highlighting are coming, but wanted to add my vote).
I love my Logos. I run L4 platinum on my MacBook Pro. I use the functions of the iPhone app regularly, but it hurts to see the app so limited when I have to be offline. I appreciate all the work that has been done to date and am thankful for what we have. I am by no means complaining. I would just like to see some improvement to this app, because it really feels second class compared to the leading Mac competitor. Obviously this is my personal perspective so feel free to agree, disagree, or just ignore me! 
Final note: I also am not in the developer's circle or anything of the sort, but maybe this all is being worked on and I just wasted my time typing this!
Thanks!
Ben