For the trigger Id say its personal preference, you have to consider that most of the new triggers on the market are copies of what companies like ZEV started. So they are all basically the same design, made by different companies with a slightly different shape on the trigger or just their logo. I believe Zev was one of the first to come out with that design of drop in trigger group for the Glock
Apex does look to be more on the flat side of trigger shapes, where Zev is more traditional curve.
Im biased as I have all ZEV'd out Glocks, they offered the most choices and options for me when I was building my Glocks, so I went with them and I couldnt be happier. I have 3 of their triggers in 3 of my Glocks, and my 19 and 17 are full ZEV guns right down to the frame mods that were done by ZEV in Cali...
The most common reaction for people that I let try my glocks with Zev trigger kits, is wide open eyes and a smile. Coming from a stock trigger that is like 7 lbs, feeling a 2.5-3lb trigger is a pretty extreme difference. Its so light the first shot is usually a surprise that gets away from the shooter. Also for me a big improvement for comfort is the flat face on the triggers, it helps me not curve my finger around the trigger so much and leads to more consistent trigger control for me compared to the stock ones