A bit of an old thread, but I will add my two cents.
I use DO, AWS and Linode to host my apps(none being meteor yet, but I am working on that too and it shouldn't make a difference since they are all just base linux machines).
To me each has a unique advantage.
AWS - Most expensive, but you get amazing features that should make your life awesome. I am not going to get into them, but I will say that elastic beanstalk is amazing, oh and you can upgrade your machine with almost no downtime. Amazon is the only one of the cloud provider that lets me shut down a machine and then does not charge me for the minutes the machine is off. You can use that feature to save a lot of money, for instance, if you need to pop up a few more instances during peak hours. One note is that amazons costs can creep up very quickly under heavy use. You pay for everything separately(storage, network transfer, minutes machine is on) and the base amounts are not huge. One big advantage is that the amount of storage you have on your machine is not tied to the size of the processor and the amount of ram you have in the machine, so you only really need to upgrade what you need. But, with that said, they offer the least amount in the way of free stuff(after the first year), for instance when it comes to data transfer you only get 1GB free a month per machine
Digital Ocean: Their 5$ 512MB machine is the cheapest offering and great when you are getting started. Overall I really like their offering, and think it is a great service, but you pay for any machine that is off and not in use, so you can't just shutdown machines you are not using right now to save costs...
Their backup service is no where near as mature as Amazon and upgrading your machine is no where near as smooth and cannot be done without significant downtime.
With DO you get a nice amount of "free" stuff per machine, but if you need to upgrade the hard drive size then you need to upgrade the whole machine and not just the CPU/Ram amount. An important point is DO gives you 1 TB of free data transfer a month with the smallest 512MB machine(and 2TB with the 10$ machine).
The "free" data transfer amount is not pooled between machines so if you had 4 512MB machines, you can't use all of your "free" 4TB of data transfer on one machine. This can be important when you scale and are using a load balancer to direct all of your traffic.
Linode: Similar to DO in pricing and features, the only difference is they start at a 10$ 1GB machine. Both services are run on SSD and from my experience both are very reliable. Linode like Digital Ocean charges you when a machine is off but not destroyed, and like DO upgrading your machine can take a while.
In Linode you also get a fair amount of free goodies, for instance you get 2TB of free Data Transfer per 1GB Machine. An important difference between DO and Linode is that the "free" data transfer is pooled and can be used across all of your machines or on one machine alone if you so choose.
Currently most of my pre meteor apps are sitting on Linode. However, I am leaning towards only working with AWS in the future. Linode and DO give you the biggest bang for your buck(AWS isn't even close). With that said they just can't compete when it comes to aws feature set and overall ecosystem. For me the amount of time and headaches AWS is liable to save me is worth the extra costs.
That's my two cents...