An unfortunate side effect of being in the industry is that I constantly have a surplus of enterprise-grade hardware at home. It's been a while since I looked at consumer hardware. Apple's Airports were solid, but have been discontinued. I've used both of the OnHubs and both were performant / stable. I've heard generally good things about Google's new Wi-Fi pucks, and Netgear's nighthawk series.
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.
My phone doesn't do 5GHz, but other than that, 5GHz is significantly better until you get about 3-5 walls between you and the router.
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.
Only have an anecdote, but when I replaced my latest (last?) generation Apple AirPort Extreme with a trio of Eeros for a ~1700 sq foot two-floor house I immediately wished I'd done it sooner.
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.
Physics is the issue here. The 5GHz band is going to be better if you are in the same room as the AP. However, it does not penetrate walls as well, so depending on your set up (and the construction of your walls), that might explain your experience.
Not OP, but we run retail stores that do cell phone and computer repair, so we needed reliable routers that could routinely support at least 10-15 clients grabbing data at any given time. We've been using the Linksys WRT1900AC (now ACS) and they've been great.
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.
For the price, I think the best set up is getting what ever ethernet only router that has your needed feature set (or just use a box with linux/shorewall), and then for wifi, running cat5 with POE to some Mikrotik wAP access points.
Is the 5G band consistently worse than the default (i.e. constant connection drops) or is that just my experience?