Yes, it does make a difference, but like with many other things you should not fall into the trap of decision making paralysis.

Your current instance lemmy.world is the largest and perfectly adequate for the majority. It also costs nothing to make accounts on other instances and is done in less time than it takes to decide between them.

That said some reasons to choose one instance over another:

Federation with other instances

Some instances choose not to federate with others. Common reasons being political ideology or NSFW/piracy/violent content. Others might be more liberal and leave it up to their users to block whatever within their own apps. As someone already mentioned world seems to have defederated dbzer0 the piracy focused instance. Some political instances that often also get defederated are the far left ones like hexbear and Lemmy grad (seems like those are defederated by lemmy.world as well).

Server location and performance

Especially country focused instances like lemmy.ca or feddit.uk will have their servers in their own countries. You can of course access them from anywhere, but a European user might have a better time choosing an instance with servers located in Europe, while someone in America might have lower latency with one located there.

Alternate frontends

If you are accessing Lemmy through a browser rather than an app, you might enjoy alternate frontends that change the design. Your current one lemmy.world for example offers 4 different designs that can also be found in the sidebar alexandrite, photon, voyager mobile and one looking like old.reddit.

General ideology of the instance

Your choice of instance might also tell others something about you. If you choose a country specific instance people seeing your profile name might assume you come from there, if you choose one with a particular political view people will probably assume you hold similar views. Same goes for other instances that are related to things like sexuality or hobbies.

It does matter.

For example, your instance, lemmy.world, blocks !piracy@lemmy.dbzer0.com

Not Jolly 😾

Captain Jack Sparrow disapproves 🏴‍☠️⚔️👑

Welcome back. You’re on lemmy.world, a perfectly cromulent instance, so I’d just leave it as is.

.world has memes and doom scrolling, what else could you want? 🥲

You’re on a good instance. Go crazy, fam.

Welcome back,

You’ll see the same communities/magazine no matter what’s the instance you use. However, some delay due to federation is possible, it’s espacially a problem with .world due to their relative weight.

The local feed means you’ll see post from your instance, which may-be interesting as you’ll see content you like if you choose a thematic instance, but it’s not a blocking feature.

Then there is a bunch of weird instance, like grad where right-winger are role-playing being leftist by shit-posting on how much they love Kim il sun or Vladimir Putin. these are defederated by most big instances and you won’t see their content (and believe me, you miss nothing)

Sort of: Each instance has its own rules, admin(s), and may or may not federate with certain other instances. Some may also be more stable or responsive than others depending on hosting.

My broad advice is to avoid hexbear, lemmygrad, and lemmy.ml because they are full of tankies/trolls, other than that: Find the instance you like best and feel free to use more than one!

I’m on Mbin these days, but when I was on Lemmy regularly, I liked to favor instances that got their power from renewables

the account you already have is goo(d)

No, it shouldn’t matter.

lemmy.world is fine, its just sometimes a bit slow. Welcome back!

Your instance isn’t on the latest version of Lemmy but that won’t matter too much.

Edit: also, welcome back. Hope you like what we’ve done with the place.

Nope! Only matters if your instance is defederated from ones you want. I like beehaw and I think they defederated from LW

No it doesn’t matter that much. Unless you are seeing too many posts of stuff you don’t like (e.g. US politics, tech news) and not enough of what you want to see (e.g. science, local content from a more regional instance, anarchist stuff, etc.), or you have a beef with how moderation is done on your local communities, then you should move to an instance more tailored to your needs.

I mean it depends on the content you want to see. A lot of instances are defederated from others because of their highly opinionated users., or questionable content.

.world is a pretty general instance that appeals to most, so it’s a good place to be.

.world defeterated with a couple of other instances accusing them of being tankies. You might be missing some content. Also, there has been some recent drama about mods at .world. Stupid rulings. I don’t think .world is a great place to be. But that’s just me.

Sometimes I post links and avoid .world because I want to ensure that they get full reach because of the defed issue.