Sequences are surprisingly limited in the control they allow over delays.
For example, there is currently no way to add a delay at the beginning of a sequence. We want sales people to be able to send a quote, then enrol the person in the sequence immediately, wait X time and if there has been no response to the quote, send the first email in the sequence that says "following up on the quote":.
The problem is that the way sequences are now, the email that's the first step can only send immediately.
I know you can customise this when enrolling people manually, but we want to use a Workflow to enrol people, and there is no way to set a delay in the sequence when using a workflow. Yes we could add a delay in the workflow, but this will then not remove anyone who does reply to the quote in the first place (hence not needing the sequence to send).
The second problem is that the minimum delay between sequences is 1 day. There is no way to trigger something immedialy, or 1 hour/minute later. Only one day. This makes no sense when you're trying to do something like "Task to call contact - completed --> send email immediately about the phone call".
Please allow more control over sequences in the same way most other tools allow, and in the same way you allow more control over regular workflows.