Fallout 4 on Survival is gaming nirvana to me.
It has everything I adore in gaming:
Superb exploration
First rate immersion
Unprecedented freedom
Very strong and endless progression
Solid game mechanics
Great loot
Meaningful scavenging
Real challenge (rare, these days)
Near perfect risk/reward ratio
I could go on, but it really is one of my all time favorite games.
It's like Skyrim, but significantly better. It has vastly superior challenge and mechanics, and it has much more in the way of distinct locations. Really an absurd amount of themed buildings with a ton of worthwhile stuff to find - including audio logs, journals, terminals and loot.
It's really quite pretty, too. Quite underrated in this way - and some of the NPC models are very, very well done.
Personally, I'd recommend a few immersion-friendly mods to tone down the time-wasting aspects of Survival mode - unless you're a true masochist.
I don't enjoy the limited inventory thing coupled with the total absence of fast travel - as you'll be spending a very disproportionate amount of time on juggling shit and moving back and forth.
I also don't enjoy having to drink/eat every 5 minutes - so I play with a timescale mod that also gives me a more immersive sense of day/night cycles.
Finally, I play with a mod that auto-saves on transitions, because that combines the fantastic tension you get from not wanting to lose progress, with being a realistic option for the kind of time I have available. I mean, I'm ok with losing 10-20 minutes of progress due to a mistake, but I don't enjoy losing hours of progress because I missed a single trap. Traps, on Survival, will kill you 9 times out of 10 - even if you sprint
On Survival, you WILL jump like crazy when a Mirelurk ambushes you from the water - or you're stormed by the undead. It has more tension in one play session than the old Fallout games had in their entirety, combined.
Like any game, it has weaknesses. The most obvious one being the writing - which ranges from laughable to decent. Really, it's not THAT bad - but there are too many WTF moments to carry the otherwise powerful immersive atmosphere.
Beyond that, I think it was a mistake to go with a voiced protagonist - as that goes against the freeform nature of Bethsoft games. I don't think it detracts much, but it represents a ton of resources that could have been better spent elsewhere.
But if you enjoy the strengths - there's no competition.