What is the best node to run at the moment?

[nc50lc]

I'm also assuming that all version of Core will have to be the same release.

It's not a hard requirement.

But there are a couple of latest incompatible releases to watch-out for (I wont mention older compatibility issues):

• If you've used v28.0+ to sync a new blocksdir, those blocks can't be used by your other v27.2 Bitcoin Core instance or older.
  This is due to the new block files being XOR'd.
• Your old legacy wallet.dat files can't be loaded to v30.x anymore with them being migrated into a descriptor wallet.

Other than those, it's relatively safe to use different versions of Bitcoin Core.

[LoyceV]

the WiFi supports Bitcoin.

As a digital nomad without fixed internet, would it be possible to just copy the blockchain from someone you know? Your own Bitcoin Core can verify all blocks afterwards, so you don't need to trust someone. Or just leave a laptop with someone for a few days to sync?
After the initial sync, even my cheap mobile data could keep up with the monthly data requirement.

[Jet Cash]

This public WiFi thing is quite interesting. I was in the Asda cafe this morning, and Core said it would take 3 days to download the entire blockchain. Now I'm in Morrisons, and it's running at about 1kB/s and transfers are intermittent. I've got a legacy wallet on an old machine with a reasonable chunk of bitcoin it it. I didn't realise that I couldn't just transfer the wallet files. I guess I'll have to synchronise that blockchain ( it's probably a year out of date), and export the wallet or just spend the coins. This node is the latest version, and I installed it using snap from the Ubuntu repository. I've got a number of backups of wallets and blockchains, and I may copy the longest chain onto a larger external drive to go forward,

[LoyceV]

I've got a legacy wallet on an old machine with a reasonable chunk of bitcoin it it. I didn't realise that I couldn't just transfer the wallet files.

You should be able to copy the wallet onto a different machine, or export the keys. But maybe easier: if you haven't moved the Bitcoins after that copy of the wallet was last synced, you should probably be able to create a transaction before it's fully synced.