Cashu is one implementation of Chaumian eCash, yes.
It is also currently the most popular and functional implementation.
Discussion
Cool. I’ve been lurking on 100 sats for the past five months. I guess they are okay’er then I expected.
How "OK" they are is entirely dependent on the mint they are from, just like how "OK" custodial Lightning is will vary from custodian to custodian. If you already have a self-custody Lightning wallet, it's never a bad idea to send your eCash balance over to your self-custody Lightning wallet instead.