I've just played through the game. I'll be including mild spoilers so if you haven't played bugger off.
Anyways I sided with the Institute. One thing I'll say right now. Don't believe the bullshit about what is the best ending. There isn't a "best" ending. The ending is subjective based on how you feel. To be honest the so called ending falls into moral grey area as no faction seems absolutely perfect. I sided with the Institute because my son was its leader.
Playing through the game I was working with all sides. I was disappointed that suddenly I'm basically forced to either attack one faction and then another. Up to that point they were all allies, every faction. Why can't you attempt to persuade all sides to work together ? Have the option to either A) wipe them out or B) make peace... ?
You're never given that option. You can dick around all you like but the npc's in charge of each faction will eventually give you an ultimatum. From that point on the entire other faction becomes aggro anywhere you see them. Where previously while wandering around you'd frequently see for example some Brotherhood of Steel guys fighting Super Mutants... well now they're fighting you.
On the endings they're all pretty much the same. You can play it through up to the point you're given the ultimatum and then just reload that save and simply betray the side you're currently with. You get a slightly different cinematic of something blowing up but thats about it. To be honest its kind of underwhelming.
Upon defeating the Brotherhood of Steel I return to the institute and random npc's are thanking me for some bandits I fought.... er what about the huge battle. Nobody comes up to thank me or ask how it went everyones just mindlessly wandering around.... um ok I'll just head out.
Well enough on the disappointing ending, the rest of the game is pretty damn good. Graphically its not the greatest although its an improvement upon Fallout 3. My favorite area is actually The Glowing Sea. Without radiation protection you basically melt & the place is full of legendary nasty beasts. Theres not much to look at but the place is intense.
The quests are great. In fact I enjoyed some of the random side quests more so then main faction quests. In particular the Cabot house quest line was awesome.
One of the main issues you'll encounter playing this game is being encumbered. I seem to always be overweight & have to find somewhere to store my shit. Every couple feet I'm playing inventory management trying to figure out what I can part with that I don't really want to just because I got some new loots. If you want to have a companion all the time you're carrying capacity is limited if you don't put many points in strength. I rarely used one to be honest, the Lone Wanderer perk is worth more then having a judgmental prick follow me around that I just met who always get in the way when I'm aiming at an enemy or set off trip wires.
Anyways... my honest review is the games good but it isn't great. After playing through once, and redoing the end I see no reason to continue playing. Once you factor out the other factions you lose out on quests. My log went from a whole bunch to maybe 3 now most of which are stupid minuteman go kill bad guys bothering a settlement.