Been playing Fallout 4 on the PC. Modded, of course.
Despite being similar in a lot of ways to Skyrim, I find I play Fallout in a completely different manner. Aside from the hoarding. If anything, the hoarding is even worse in Fallout 4 since you can use pretty much anything to make something else. Also, in Skyrim, I tended to roleplay my characters. In Fallout, I just have the one character, and have no intention of starting others, though looking through the perks I came up with all sorts of themed character builds. My character is basically a big boy scout...the commonwealth has a great need for such people, after all.
I liked Ada...until companion A.I. started shoving her right in front of me every time I moved, looked at something, or turned around.
Piper was fun, and I like her style...I kind of get the impression she is intended as the main character's main love interest.
Cait is awesome. An Irish woman with a double barreled shotgun who talks about getting drunk and starting fights all the time.
The quests are the same basic thing as Skyrim: Go somewhere, kill everything that moves, get item. If it ain't broke, don't fix it.
Deathclaws are terrifying. Way scarier than anything in Skyrim; they're like raptors on steroids.
Different flavors of raiders are everywhere. Supermutants are wherever the raider's aren't. Mirelurks are annoying, but not nearly as annoying as the most annoying enemies in Skyrim (Falmer), so that's a plus. I do like how the different factions can often be found fighting each other.
One thing I noticed that you might not have if you've never played Fallout 3...When you blow up an enemy at close range in three, parts go flying everywhere and sometimes bounce off the screen. Despite playing Fallout 4 for 30+ hours, I have yet to see an eyeball bounce off the screen. It's a little thing, but it is little things like that that add to the gameplay. Oh well, not a big deal.