I really like GoCardless but feel that customers might be hesitant to enter that information, especially when they're not used to doing it.
We have found that conversion can be just as good, if not better than cards in the right cases. The biggest factor that affects this is transaction type.
We see really great conversion for repeat billing where Direct Debit is already a well known method of payment. Conversion is not as good for one-off payments where DD is less expected though.
I was considering GoCardless but a survey of my customers stopped me.
Some people have funny ideas about how DD works, not realizing it's extremely consumer friendly and much smaller fees than credit cards.
I was thinking of offering both as my brief play with GoCardless was very easy to implement.
That's what we recommend. It's super easy to sign up and integrate so it's absolutely worth signing up and just giving it a go. That way you can see whether it works for you and your customers.