What was your reasoning for your choice? Do you believe you have made the right choice in the short and long terms?
For our clients and our own projects we've switched to using our own servers/VPS's.
I think PaaS is great for getting simple apps up and running that don't have a lot of external dependencies. However, the PaaS I used (Heroku/EngineYard/AWS) don't perform good enough compared to VPS or servers at "traditional vendors" or things like DigitalOcean.
Also, some of our customers need to have their servers in a geographic location close to home or under national legislation and they don't want to be dependent on a "massive" infrastructure where they can't just pick up the phone and call someone.
Also with local vendors. Problems are usually solved more quickly and communication lines are shorter. You have an answer on a problem much sooner. It also helps that these local vendors do not have massive infrastructures that are hard to fix or hard to move in a short manner of time when something really bad is going on. I have better experience with smaller traditional vendors in fixing problems than I have with "the big guys".
Heroku, for example, is largely dependent on AWS. If AWS fails somewhere, you can't just move somewhere else. Because the deployment procedures and infrastructure is vendor-specific to Heroku. You're kinda locked in. Addons for external services like Redis, Search daemons, logging, etc. is great for ease of use. But if some of those hip startups die, don't get funding or they just have technical/security problems you can't "just move away" because you're pretty locked in.
The above reasons are some main reasons why we moved to 100% of our own servers at local vendors. We have some at DigitalOcean and some at TransIP, which is a Dutch vendor with a long track record and we can by without a credit card with "regular" Dutch payment methods and contracts.
The main problem with "do it yourself" servers/VPSs seem to be the time and effort you need to put in to get everything up and running. PaaS services take care of all this for you. This comes at a price both economically and technically. If you're fine with that price, than I think PaaS is good for you.
If you're not "fine" with that price. You run into the problem of reading through guides, documentation, fiddling with your servers, keeping them updated, managing security, etc. etc. All kinds of problems you need to solve.
Luckily, there is Managed Hosting at some web services and applications that takes care of all this. There's stuff like Plesk, DirectAdmin and such. But they are pretty outdated and not really useful if you're a Rails company.
Luckily, you can use a service that does server/cloud management for you like Commando.io, IntercityUp.com or Cloud66.
Hope this helps!
It's turned out to be an excellent business decision, saving me a significant amount of money.
I wrote a blog post about the whole thing a while ago, actually, talking more about the comparison: http://www.mmomeltingpot.com/2012/03/wpengine-review-after-1...
Ironically, the site that review is on is one of the few I no longer host with WP Engine, but I still have something like 10 other WP sites running with them.
https://blog.engineyard.com/2014/pets-vs-cattle
My summary here would be that both are good, for different things. If I was deploying a personal site or a personal app, I would probably go with a VPS, because it's easier to set up, and can be a lot cheaper. But if scaling or uptime was a concern, I'd want to go the PaaS route. It comes with a few upfront costs (configuration, statelessness, price, etc) but is absolutely worth it in the long term.
The only thing I use VPS's for now is testing. I just do basic security hardening and call it a day. Not really too worried if anything happens to these boxes.
I saved A LOT of time switching to PaaS's. Probably 30-40 hours a month. I don't really touch anything sysadmin related anymore and I'm a lot more productive.
I don't regret using VPS's because it forced me to learn alot of sysadmin stuff.