I'm a Unifi shop and nearly 100% of my clients use Apple products, can't remember the last time I saw someone with an Android phone. No complaints from any of my users/sites about roaming. My rules for deployments

1) When you layout your APs you will likely need more than what you think. 5ghz doesn't go as far, and as dsp suggests, you may need to turn off the 2.4 radio on some APs for the sake of getting the 5 to cover the entire house.
2)I'm bringing an AP to my initial project meetings to get everyone to understand these things need to be seen to be effective. I'll still go for the top of closets or cabinets if I can but hallways/passageways between rooms is often the best placement.
3) Using analyzer software like Wispy to tune my installations. Use this to set channel spacing and power levels. Speaking of power levels, unless it's just a single AP I find that the APs work best at 1/2 to 3/4 power levels which means I need more in my deployments. See #1 above

One last thought, the OP didn't mention his/her preferred wifi hardware vendor but I'll say having all your APs in one pane of glass is really helpful when tuning the site. Unifi, Ruckus, OpenMesh, Meraki and others

Anyone can afford that.

when did anyone say that a Ruckus Zone Director with 4 APs was affordable for everyone?

AOC is attempting to push through legislation so it can be free to anyone that wants it and "not willing to work". "Its just not fair that home with wheels dont have access to this!"

If the zone director is too expensive and you will not need more than 25 ap's for your project, then just purchase the ap sku's for unleashed.

Unleashed is the virtual controller ran on the master ap of the system. Any ap you add after configuring the first one gets added automatically to the system.

Majority of my Ruckus systems are all Unleashed. I'm talking under 6 ap's total for most projects. Set it and forget it. In the 7 years using Ruckus, I haven't had one single callback for wifi related problems.

AOC is attempting to push through legislation so it can be free to anyone that wants it and "not willing to work". "Its just not fair that home with wheels dont have access to this!"

Yep, his nose is so far up Hannity's cheeks can't see anything but what he wants. Same ol' with him.

Do you do anything special in the settings to get devices to stop sticking to weak access points with Unleashed?

Just tune power levels and RSSI settings. Everything else I pretty much leave alone and let the virtual controller handle.

"I" devices are the worst clients by far. I usually set RSSI between -80/-75, seems to do the trick for them.

I have one particular site that receives zero cellular service from any carrier. The customers all use their cell phones wifi calling to talk to customers. If handoffs weren't working properly, I'd certainly here it from these people.

When I find "I" devices being sticky in a certain area, its usually the outskirts of the system. If client wants better quality in that area, another ap goes in.

Same client from above, they have an outdoor patio (basically the roof top from the floor below them). This area wasn't part of the initial design for wifi but still received "OK" signal. But this area was right where an overlap occurred and would sometimes stick to the weaker ap. Slapped an outdoor ap out there and problem went away.

There is only so much that you can do with stubborn devices.

I saw in unleashed you can set power levels for each radio but what about RSSI thresholds? Or is that just turning on and setting load balancing? Trying to learn :)

In my experience RSSI might vary inch by inch and can be dependent on placement of bodies in the area. Unless there is a dramatic difference between the RF level of competing access points, why wouldn’t the poor client flipflop between access points, potentially spending more time flipping than communicating? Hysteresis might help, but I don’t know how one would set the level and time constants.

LOL stuff like this makes me think of what it must have been like when the United States decided to build roads. Some crazy socialist lefty thought we should have sidewalks and roads that connect the country. Conservatives fearing that "not willing to work" people might also use the sidewalks and roads.