Since I moved to WP, I have been a great fan of BlogVault. This India-based backup and migration service has proved very reliable, offering also one-click restore and staging options. More recently, it has added plugin management. Warmly recommended.
Moving sites to ClassicPress and losing the security and other adantages provided by BlogVault would have meant a real step back for me. I asked BlogVault support. A week ago, I have received the following answer:
BlogVault will work on ClassicPress. All our features will work the same
Of course, I will test it in due time (waiting for post-beta v.1), but those have been great news for me. I assume that other CP users or future users might be interested as well.