First, this is my experience with 3 different devices — your experience might be different. As many reviewers have said, practice is key to have comfort with these devices when using outdoors. Try first in the shower, then at home in the bathroom before trying outdoors.
With all of these, zipped pants/shorts work better than drawstring ones, as you can unzip and not need to pull down your clothing. For the Freshette and the EllaPee, you can use the hand not holding the device to pull your underwear to the side.
I've had a P-style for years and used it occasionally. Pros: single piece of hard plastic that doesn't collapse. Easy to store and clean. Smallest of the three devices. Cons: open at the top so spillage is more likely. Using the hard plastic to 'wipe' needs care. Can't easily pull underwear to the side and use it without risk of spilling/leaks.
I also have a newer version 'Freshette' and have practiced with it but not used on hikes. Pros: the design 'cups' your ladybits and the open area is closed against your body so reduces spillage possibility. Silicon is fairly rigid so doesn't collapse and isn't as hard a material as the p-style. Cons: the tube connects to the body of the device and is an obvious failure point if not *firmly* sealed to the body of the device. If you make sure it's fully sealed at home, then that might not be the case after jostling around in a ziplock in your backpack.
The EllaPee for me is the best of the trio. Pros: also cups your ladybits and the top/large opening is closed against your body. The main portion is soft silicon with a harder silicon support structure. Single piece to reduce failure points. Easiest of the three to use when wearing zipped pants/shorts and pulling underwear to the side. Cons: it's larger than the p-style but smaller than the Freshette. The bag it comes with is big enough only for the device, so it won't carry any wipes to clean either yourself or the device–but that's a really minor con for me.

Oh my God! This is it!! Actually it is the only one that works, at least for me. This, and the perfect gotta tinkle that i've been using the last 5 years and the perfect PP-aid that I've been using the last month . The last 3 months i have spent so much money to find something that i can use without pulling the trousers down and without scuatting . And since i order almost all of them from usa to greece, the expenses are way more. I have tried pstyle and tinkle belle that are similar to each other and to ella pee but you never know if you are going to pee all over yourself with them, plus they hurt a bit trying to make a seal.
I have tried sunany and su amiga (bought 2 of them 🙄 ) but they don't work at all. I have tried the shewee and the shewee flex, they worked sometimes but not to trust them..I have tried the pibella that is really good, except that I can't always put it right plus it hurts sometimes or if you use it often. Although it helped me a lot when i had to collect urine for 24hours and i had to poop also, so with pibella it was very easy to make the 2 business simultaneously but in a different place.
So. When i received ella pee i thought this is the last one, and i thought that it won't work either or i wouldn't trust it every time. But…i have used it over 20-30 times at home and with tight leggings without having to pull them down and with very heavy flow, when you can't wait anymore to pee, and there has been not once any leak!!! At the time you start peeing you think you will get messy as you had with all the other fuds but you don't! It is perfect!!! I have tried with a bottle, at the toilet, and at a traveljohn. I'm looking forward to tried it outside, where i need it the most, like at dirty and narrow toilets where you don't have space for trousers down. I also have to say that i am about 100 kilos and it works perfectly for me. You just put the front part at the end of your front opening down there and the rest part finds its way by itself .
It doesn't leak and doesn't overflows at all the way it is made!
I have already bought my second one and will definitely buy more if this! Thank you!

I purchased this and the Venus to Mars female urination devices to try this stuff out. Similar price, utility, and included carry case. I thought I would like this one better because of the soft silicone rim and the enclosed exit tube, but when I've tried it I've found that it can be hard to aim the stream of liquid because sometimes it will come out in like a spiral through the tube and constantly change direction. I didn't have this problem with the Venus to Mars. It's usable, but I have to be more careful with aiming. Otherwise, the fit and comfort level were fine. It is larger and bulkier than a device like the Venus to Mars, so a bit less discreet. Maybe it would work better than the Venus to Mars if you needed to pee in a bottle? But I have not tested this out.