I've used them both pretty extensively as well as Red Hat based distros. For me there's a few minor, but important enough to make me stay on pop, differences:
1. It uses systemd-boot as the boot loader. I like not having a grub menu, just turn on my computer and I'm basically on the login screen. It's seamless.
2. Flathub enabled out of the box. I find Flatpaks the best experience for lots of common apps like Slack, Teams, etc. It's a nice feature.
3. Nvidia support in the ISO/out of the box. Nice experience for Nvidia GPU users.
The rest of their stuff, like the windowing features etc, I don't really get much value out of. I like Gnome so I disable most of their stuff.
I really apologize, but this answer only made me even more confused:
1. I don't get the grub menu on any of my Ubuntu machines (except for the one I use to test stuff where many distros co-exist); I "just turn on my computer and I'm basically on the login screen. It's seamless."
2. Same. But with Snap. (I know that many people here don't like snaps for many reasons, and I do too, sometimes. But experience-wise, they're fine and comparable to Flutpaks. It's even possible to add Flathub if one's into that);
3. Installing Nvidia drivers is easy. And they're in the Ubuntu ISO since 19.10;
Installing Nvidia drivers is easy if you know what you're doing.
For the last year I installed both Ubuntu 20.04 LTS and 21.04. Both times I had to opt out of installing proprietary drivers during installation to avoid getting a system freeze. Then, on first boot, I would open a new session before I even log in and install updates and nvidia drivers from there. Any attempts of using the GUI to install them would result to freezing. With Pop I never had to go through these loops, I just installed the Nvidia ISO and I was good to go.
I also get grub menu on startup with Ubuntu. It's like 3 or 5 seconds long but it's there, and I use EFI. But it's not a deal-breaker.
> 2. Same. But with Snap. (I know that many people here don't like snaps for many reasons, and I do too, sometimes. But experience-wise, they're fine and comparable to Flutpaks. It's even possible to add Flathub if one's into that);
Snap is much worse at dependency sharing than Flatpak, which is surprisingly okay at it despite the container-based approach. This means that after you install your first one or two Snaps or Flatpaks, Flatpak is several times faster than Snap.
Snap has pretty atrocious download sizes and install times, plus noticeably slower app start times, even on NVMe and very fast internet. I definitely recommend directly comparing them.
(Keep both around of course, to leave whichever as a last resort for what's missing from the other.)
It has been a while since I used vanilla Ubuntu, so I apologise if some of my answers are outdated. Last I remember the Grub menu was still there. But yes for point 2 my view on Snaps was largely based on third party comments about the safety/usefulness of them compared to Flatpaks, much of which is may not be accurate any more as I've seen large projects (like Certbot) switch exclusively to Snap.
> 1. It uses systemd-boot as the boot loader. I like not having a grub menu, just turn on my computer and I'm basically on the login screen. It's seamless.
For those on other distros wondering about this behavior and whether they can get it: systemd-boot does support menus, and GRUB also supports bypassing the menu. Systemd-boot is quite good though. It's simpler to configure and less feature-complete than GRUB, and a great first choice for EFI setups.
1. It uses systemd-boot as the boot loader. I like not having a grub menu, just turn on my computer and I'm basically on the login screen. It's seamless.
2. Flathub enabled out of the box. I find Flatpaks the best experience for lots of common apps like Slack, Teams, etc. It's a nice feature.
3. Nvidia support in the ISO/out of the box. Nice experience for Nvidia GPU users.
The rest of their stuff, like the windowing features etc, I don't really get much value out of. I like Gnome so I disable most of their stuff.