I hate to have such a negative title, but I'm just curious if I'm the only one noticing this. I used Logos 5 for a few minutes about two weeks ago on a Retina MBP and didn't think it looked that bad. I went ahead and did the crossgrade to Logos 5 a few days ago and now I'm honestly annoyed to look at it on my pre-retina MBP.
Logos 4 was always a little annoying because it never looked completely like a Mac app. It wasn't terrible, but you could always tell that it wasn't designed for a Mac. It reminds me of when Firefox used to stick out so badly on a Mac. Well, after several days of working with Logos 5, it looks even less like a Mac app than Logos 4. The more I try to work with it, the more I feel like I'm looking at a Windows app. This may seem like a small thing, but the inconsistency really stands out. The visual design of Mac is one reason many of us prefer it over PC's and it looks like Logos has taken a step further away from the app looking natural on a Mac and basically locking everyone on to the way a PC looks. Granted, Logos began as a PC app, but these little polish elements are important to many of us Mac owners.
I'm really not trying to sound negative or complain. Obivously I may be much more "right brain" than many people on this forum. I'm just being annoyed with how much Logos 5 sticks out on my computer and makes me feel like I'm switching back and forth between a PC and a Mac in the middle of my workflow. That's why I'm curious if I'm the only one noticing this. The design consistency between Logos and everything else on my Mac is so great that it's enough to make me want to work outside of Logos when I can with a certain other Bible software package.
No offense to all those at Logos who worked so hard on Logos 5. I do appreciate the increase in polish over Logos 4 
I'm also not trying to be negative. I plan to send this feedback as a suggestion to the appropriate channel at Logos but I'm wondering if I'm the only one affected by this.