D&D 3E/3.5 5e: Is it really lower magic/less gonzo than 3e?

[The Crimson Binome]

That's not quite how it works out.
You aren't going to have a +4 in your secondary stat unless you are rolling stats. You are realistically looking at a +2, maybe a +3 if you have one of the races with a DEX boost. Then you have to figure in accuracy: Not only will you be hitting more often with your (higher than DEX) casting stat, numerous cantrips have the benefit of not requiring an attack roll, and thus ignoring the penalties of cover. Given that your own parties melee squad gives the enemy cover by simply being close enough to stab them, you are going to be sitting on an additional -2 to -5 penalty for crossbowing most of the time.

You could also have a Dexterity higher than your casting stat, depending on which spells you pick, and other factors.

Likewise, whether or not cover is a frequent concern, is something that will vary alongside a number of factors. Your melee friends only provide cover to your enemies if they are actually between you and them; and even then, you can often solve that problem by moving to get a clear line of fire.

 

[Ashrym]

Weighing in on crossbow vs cantrips. I often leave out the attack cantrip and go weapons and then pick up the attack cantrip later. Weapons are better at low levels.

That doesn't eliminate cantrips existing and spammable either way. That means I can cast mage hand, minor illusion, prestidigitation, and rituals on a wizard and nearly the same on a bard.

It doesn't take attack spells to have that increased sense of magic. It takes a certain amount of at-will magic.

If a DM really wants a less magical campaign, restrict classes allowed in the campaign that provide a lot of magic.

Use the alternatve options for resting including healing and the optional lingering injuries table. 5e is not more like sword and sorcery by default but it does provide options for dialing it up or down. Permanent injuries, recovery times for healing and magical healing not an option, medicine checks needed to treat diseases, etc are really that easy to incorporate into the campaign.

The game is what the group makes of it, not the defaults, and it definitely provides some concepts to change it up a bit.

 

[Oofta]

One of the pitfalls you may want to avoid (at least at first) is the magic-mart. Allowing people to buy whatever permanent magic items they want will in general lead to more powerful PCs.

It's not necessarily a bad thing depending on what you want in your campaign. if you use the standard rewards as listed in the DMG, PCs will get quite a bit of gold at mid-to-high levels. The baseline assumptions of 5E seems to be low magic and probably no optional rules (feats, multi-classing, etc.).

As an aside one other house rule I have that I forgot about was that ability items (i.e. belts of giant strength) add to abilities instead of replacing them. This is in large part because I do allow PCs to buy items with rarity based on their reputation and I don't want that guy that has strength as a dump stat suddenly being the strongest person in the party.