5G is the better of the two bands - it gives you many more channels and there's generally less interference. That sounds like something particular to your environment.
If you have a Mac, I recommend installing Wi-Fi signal (https://itunes.apple.com/us/app/wifi-signal/id525912054?mt=1...) - it gives you much greater insight into what's happening on the air. I'd start by installing something like that, and monitoring for correlation with your drops - what else happens when your connection drops? Does the SNR drop? Does the AP change channels? etc.
Great. Which do you like best ?
In general, 5GHz is way better for apartments (less channel congestion, apartments are usually smaller than houses), and 2.4GHz is better for non-urban houses (better wall penetration).
For urban houses (I can see 15+ 2.4GHz networks from my living room; in a larger city it could be worse), the best bet is to have 2 or more APs and connect them with ethernet if possible, and powerline otherwise. My cable internet comes in the house in the corner of the house, and is under a different roof a-frame than the rest of the house (a previous owner built living space above the garage), so I can't run ethernet through the attic, and I use powerline adapters; there's a separate subpanel for this area too, but I still get minimum 30Mbps over the powerline, which is good enough for web/e-mail.
My next step is to see if any outlets under the main roof get good signal over the powerline, and then run ethernet throughout the attic; then I can have several routers throughout the house.
I use TP-Link APs running OpenWRT; they are cheap and OpenWRT lets you adjust the power down. If you aren't cost-constrained, I've heard almost nothing bad about Ubiquity.
Expensive for sure, but setup was a breeze, reliability has been great, and I get 200Mbit+ a floor away from my ISP router, where I used to see 20 on a good day.
I was skeptical of how well a mesh could work, but the performance has sold me.
I have one here at home as well. I'm on a Gigabit connection provided by AT&T at home, and the router sits two rooms away with 2 walls between me and it. Also, my daughter is watching YouTube videos using it right now. With all that, I just ran a speed test using fast.com on my iPhone 6 and it showed 150Mbps. Really solid router.
Is the 5G band consistently worse than the default (i.e. constant connection drops) or is that just my experience?