I wasn't familiar with opreturnbot.com before - thanks for sharing! Looking at it, I'd say the general idea is the same, except the message is stored in a taproot inscription rather than in a OP_RETURN output, so you're not limited to 80 characters.

Two other minor differences:

1. opreturnbot.com requires payment by lightning and takes temporary custody of your funds, whereas btcscribe.org is purely non-custodial
2. Since there's no server or lightning node to manage, btcscribe.org is probably simpler for someone to clone and run locally.

Hope this helps!