My progression has been PaaS -> AWS -> Digital Ocean -> Dedicated and I strongly feel that if you're going to make the leap from PaaS to VPS, it's not a whole lot harder to go dedicated and there you'll find much sweeter value. I'm currently on an OVH SP2 (Xeon + SSD + 32GB ram in a data center in Quebec so not terrible latency to where I am in the northeast US) that I pay $90/mo for (http://www.ovh.com/us/dedicated-servers/sp2.xml) and it's just jaw-droppingly powerful. If you're going to go through the trouble of migrating your app anyway, it's worth taking a good look at dedicated offerings like that as well.