Finished it. In the sense that I completed the Railroad storyline, and the only missions left are clearly randomly generated ones like "clear ghouls for this settlement." I hit level 70 shortly before reaching that point, which I guess shows that I like to dawdle. There's a lot unexplored, and I got maybe 30% of the bobbleheads.
High Charisma mattered more toward the end. Seems like there weren't many meaningful speech checks until fairly late in the story, but there were definitely some then. Ones that let me get around what would probably have been some fairly stiff firefights.
I never once fired off a missile or mini nuke. Mainly because I didn't want to lug the weapons around, and they're not much use indoors, where a lot of the action happens.
I spent a lot of the late game exclusively in my power armor. I had 30+ fusion cores, and the massive difference between the defense of well-upgraded power armor and regular equipment's pretty significant, and there aren't many drawbacks. I think sneaking's a bit harder, but it's not that hard with Sneak 5, and I was getting lots and lots of 5.4x stealth bonuses.
The oddball weapons - syringer, junk jet, railroad rifle - came way too late to be useful. In each case, by the time I found them, they sucked compared to the conventional weapons I already had. The Railway Rifle in particular came ridiculously late, and was way outclassed by the fully upgraded assault rifle I was carrying.
I'm thinking about how I could play through differently, if I were to start over. I started with a high-INT, mid-charisma character and focused mostly and crafting stuff. I eventually went high-stealth, since Bethesda games always seem to reward that. My initial agility was pretty low, so I had to take a lot of points in Agility before I could unlock the Mr. Sandman / Ninja combination. I never had more than 1 luck, so the critical-focused stuff was largely unavailable.
Obvious alternates are a high-luck, critical focused character, or a high-strength, heavy weapons / automatic weapons focus. High luck and high stealth don't go so well with automatic weapons because they focus on doing a lot of damage per shot for higher sneak and critical damage.
I have no interest in pursuing a melee build. Way too much happens at long distance, futzing with guns is more interesting, and the game's so chaotic at close ranges I tend to resort to VATS just so my character will track enemies that go flying past me at point blank range.
I think Demolition Expert is nice, but I have trouble seeing the value of the Perception perks above 5. Sniper is the most appealing one, but the bonuses are small - it's not hard to keep a scope steady without it.
The Endurance perks just suck, period.
It's difficult to imagine playing without at least Int 4 for Hacker and Gun Nut, and Science! is pretty darned nice too. Particularly if you use power armor extensively, since it's required to make the truly durable Power Armor upgrades.
Part of me thinks I should eschew power armor entirely, since it makes the game much easier and short circuits the armor upgrade system. Except that I already played one game where I spent a lot of the early game avoiding using it because I was hoarding fusion cores. I wonder how much easier the early game would have been if I'd been more willing to spend them.
I think maybe Fallout 3 had the right idea in making Power Armor require training, and not something you could use until very late.