So I'm most of the way through the current game solo prepping for the last boss. It's a no portal run and I'm on day 115. Had a previous playthrough with a friend where we got to the same point until he found something else to play.
The first points are on the aesthetic side of the game. I really like building compact but pretty bases. One issue I always run into is stuffing all the work bench and forge upgrades next to their proper counterparts. If the 'upgrade distances' were a good bit longer I could place them in nice looking positions around or outside the base that make aesthetic sense. The adze and smithing anvil right next to my eating table? Yikes!
I managed to move the smithing anvil to an outside wall and create a little scene with a chair and whatnot to make it look legit but the adze sadly sits stuffed in a corner of my base. The designs are great, let me integrate them into my builds!
I'd also love a way to integrate the smelters and furnaces into a nice kinda outdoorsy smithing/metalworking type shop but maybe here I am just not creative enough.
Lastly I'd love a way to keep exposed wood from decaying from exposure. We all have a ton of resin and it would be nice to 'treat' the wood so it doesn't lose durability when outside. This would also let the player decide which pieces to treat or not giving them more control over their builds.
As far as portals my viewpoint is probably in the minority but here goes. I think they destroy a lot of the core gameplay loops that make the game so satisfying to play. On the playthrough with my friend we used them extensively and they joy of exploration was greatly diminished. New land with a possible beautiful build location? Just put down a portal and fence it it.
Things like wet debuff and rested also mattered far less since a body recovery was always 30 seconds away.
It removes much of the forced choice aspect that makes the game so tense in certain situations. Choosing to sleep (or not) in the wrong bed can totally wreck what you were doing and gives each decision significantly greater impact. It also gives players less incentive to develop their character skills since fresh item buffs are a portal away. Paradoxically it makes gathering materials a chore since portals give you easy access to the next objective rather than free roaming.
Anyway this got way to long and that's my two cents. It's a great game no matter how you choose to play it.
Edit: Bad wording.
Source: https://www.reddit.com/r/valheim/comments/n0rfcm/a_couple_little_commentssuggestions/