Pick your attackers or take game's choices?

How do you define "better results" ?

Gym taken, mission acomplished - the result is the same. The differences are ressources used - time, potions, revives.
It is about 20 seconds to look the gym throu first, switch to alphabetic order in pkm-list where my attackers start with "#" and stand at first position, and chose the right attackers in the right order.
I assume, i save this time when having shorter fights. Maybe i am more potion-revive-effective too.

When there are one or two defenders only and the games choice is not so bad, i usually dont change.

Much better results, sometimes the game suggests horrible attackers, especially when the defenders are of different type.

I always pick my own attackers. I think it influences the time spend on a gym the most. Having a water vs water fights takes much longer than grass vs water for example.

I hate the auto selection choice most of the time and they love to lead with the worst choice too. My defenders are my biggest mons and they're usually the first 4 chosen & in the wrong order. The only two defenders I attack with are my eggs with seed bomb since I still haven't gotten a good grass type attacker and they're usually first two slots when I wouldn't use them usually until the gyms 4th+ choice. It also loves picking out my maxed vapes defender when my near maxed vapes attacker is far superior. So I'm constantly having to switch mons around or switch them out. It wouldn't be so bad if it was just reordering but it's switching out and reordering. Like an hour ago I ripped down the blue gym by my work. The gym order was eggs snorlax vapes gyrados rhydon dragonite rhydon. Their selection was eggs eggs vapes(water pulse) vapes(hydro pump) snorlax(ZH/BS) vapes(2200cp aqua tail the smallest choice) my edited list was arcanine(bite FT) eggs vapes(hydropump) jolteon jolteon lax(lick BS). I only used 5 of the list 3 of which ended with low hp the other 2 about half. After the first 2 rounds the arcanine & snorlax werent used anymore I left the 6th slot with whatever filler. I would love to set certain mons as priority attackers even if I had to reorder the list.

I choose my own Pokémon. Though there are times that the choices aren't really that bad but I for sure can do better than AI. I don't usually need 6 mons. 4 is enough. Even if it is level 10. I try to dodge everything.

I almost always pick my own Pokemon. The auto select tries to type match things... but it absolutely loves picking my Water Pulse Vapes even though I definetly do NOT want to attack with those, or just puts things in the wrong order.

Though I will say that against a single type gym it usually does a very good job. "Oh there are just Vaporeons and the game put Venusaur and Vileplume first? Cool, let's go."

I almost always pick my own team because, to me, the fun of battling is using different mon for different situations. I have my favorites that I simply enjoy using (like Charizard) but also enjoy trying out newly acquired ones to test them out (like my relatively new MS/EQ Rhydon).

The game almost always leads every fight with my DB/HB Dragonite, and I'll sometimes just go with that w/out even looking at the rest of the team's lineup if I'm in a hurry and it's a level 3 or lower. Otherwise, I pick.

I have often wondered how the game picks the team. For about a week or so, it insisted in choosing a mid-level Golbat every time, and I'd be all WTF? I decided to actually use it once to see if the game knew more than I did, and my Golbat got its ass handed to it.

Choose mine always.
Game's automatic ones are often terrible, and don't take into account the first opponent you are going to battle.

Very good question.
About 70% of the time the Auto-Select gets what I want. I don't know about the complete mechanics behind, yet I'm throwing out some examples and findings as below:

1. If the gym has only Gyarados, Auto-Select would choose my Jolteon. Correct;
2. If the gym has only Rhydons, Auto-Select would choose my highest CP Vaporeon (pulse, unfortunately). Half Correct;
3. If the gym has only Dragonites, Auto-Select would choose my Jolteon. So wrong!
4. If the gym has only Vaporeons, Auto-Select would choose my Dragonite. Correct (Some might argue why not Grass Types, my reason is simple: Dragonite takes down Vapes faster);
5. If the gym has only Snorlaxs, Auto-Select would choose my Dragonite. Correct.

However, when the gyms contain different species, it won't work so well.

My findings are:
I. Auto-Select seems to give priority to Pokemon with following features:
1. High CP;
2. Favourited;
3. Full HP.
II. It seems that it won't consider move set.

The biggest problem s that if a pokemon has even a small bit of HP nocked off, then auto-select passes over it.

The first time I get to an enemy gym, while my big attackers are all fully healed, the auto-select works pretty well. I might switch the first pokemon and switch out a few of my big defenders that were selected for other attackers. The second fight though, my big attackers which are now only down about a quarter HP, become taboo for the auto-select.