Which size would be better for LOGOS?
I'd say 15.
Logos will work well on any of the MacBook Pro's regardless of the screen size. Probably the only question would be in the 13" models whether to opt for the Retina display (there is currently one model without a Retina display but with an optical drive). The Retina displays are stunning in clarity ... in whatever size.
I have one of the new 13" rMBPs and it is great. I usually have it hooked up to an external monitor when using Logos/Verbum, but it isn't necessary to do so. The SSD is key.
Any suggestions comparing a 13" MB air to a 13" rMBP?
Yes, one big comparison. The standard 13" MacBook Pro is upgradeable - memory, hard drive or an SSD. Or you can even have both if you remove the optical drive. The retina MacBook Pro is not upgradeable. If you intend to buy the retina model, order it with as much memory and as large a SSD that you can reasonably afford.
In Christ, Charles
If you intend to hookup the laptop to a monitor most of the time, retina won't matter much. The processor speed on the Pro is higher, but at a hit to the battery life. I previously had a 13" Air, and now a 13" rMBP. The Pro is a little heavier, w/ a smaller footprint, obviously a better screen and speed, but you still won't be playing any 3D games or doing anything too intense with it.
I just got my first mac last month, an rMBP 13 2013, and I love it. The screen is great, it's super fast with the SSD, and the trackpad is incredibly intuitive. I would say your selection will really depend a lot on your needs. I would not recommend the Air, personally, because the pro has very good battery life this year and the retina screen is wonderful for reading. The 15' will give you a significant boost in screen real estate, which is always a good thing. Yet, it's also a pound heavier and costs a good deal more. I personally chose to upgrade the ram to 8GB and the SSD to 256 (standard options on the 15'), to give the computer that much more power and a little room to breath with the hard drive. Yet, it was still about $500 dollars cheaper than the 15'. If you need more screen real estate, a monitor to use as second screen is always helpful. There are also great multi tasking options on the mac. Go to mission control, put logos on one full screen desktop and your word processor in another, and then you can swipe three fingers to go back and forth quickly (that is if you use a word processor and logos at the same time )
Yet, if you have the cash and you don't mind the weight and lower battery life, I would recommend the 15'. My opinion is that it's well worth the money if you have the extra to spend. Personally, while I have the 13' and love it, I would love the 15' that much more.
One last thought, if or when you get a rMBP, consider getting applecare. Apple covers their computers hardware for a year, and applecare covers an extra 2 after that. rMBPs are costly to repair, because it all has to be done through Apple. One bad battery will pay for the cost of the coverage. You can also find it a little bit cheaper if you check ebay. God Bless!
Since you asked about size in particular, I'd say the larger the better for Logos. Logos is an application that will make use of all the screen space that you have. The more real-estate you have, the more resources or tools or whatever you can have open, with enough room to read the material on them, at one time. The smaller the screen, the less you can fit on it; simple enough.
Aside from screen size though, other benefits to getting the 15" rMBP over the 13" is that a non-upgraded 15" is going to be more powerful than the 13" (though the best base 13" has more SSD storage than the lowest 15", which could be a reason to choose the 13" unless you plan on upgrading the SSD on the 15"). And Logos is an application that will make use of your computer's power.
I'm the kind of person that tries not to spend much money on wants. I believe being a good steward naturally entails sacrificing material pleasures to be able to use your resources for other, more eternally valuable, purposes. But with that said, when it comes to computers, I buy the best computer I can afford. Not only are slow computers incredibly frustrating (to me at least), but intensive applications like Logos work so much better on more powerful equipment. The investment toward a powerful computer is worth it, in my opinion.
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