Basically this is true and this leads to the conclusion that instance types like (micro, small and medium) are quite underpowered compared to "today's" usage patterns right?
Of course Elastic Scaling is not possible. Because Hosting a server in a datacenter and having cloud instances are two different stories. If you have need for flexibility you can simply run a loadbalancer having your base hardware hosted for a good price at hetzner (or another datacenter you like) and then spin up some AWS Instances behind the loadbalancer for dealing with spikes.
Or as others have written you can buy 3 boxes at hetzner and scale 300% ;)
The problem is that you need to have all the three boxes on the same rack wired up to a gigabit switch. Hetzner can do that for you but you can't add or remove servers easily.
I have found that OVH has a virtual rack that can accomplish this. After years with Hetzner I think it is time to move on
Do you have data for the difference in latency &/or bandwidth between servers on the same rack at Hetzner vs. on different racks?
I was assuming that having the servers in different racks would be an advantage, mainly because the reason I have multiple servers is for data redundancy (I'm using Riak and data is replicated across the cluster.) However, in Riak the servers do talk to each other a fair bit.
The latency and bandwidth between a given server and a web browser out in the world shouldn't vary much from rack to rack, I'm assuming.
Sometimes i had a 5-10% ping loss between servers in the same Hetzner datacenter, so not being on the same rack can be a problem. Especially if you are using nginx -> backend. Then every request is a TCP connect to the backend server, and when SYN packet is lost, you will have a 3 seconds timeout (at least on FreeBSD TCP stack).
In my opinion a very good choice. I run a EX4 Box there and i'm more than satisfied with the service they provide.
Recently i fired up a Support Request around 5am and got a response 6am when their support team picks up work. during the day you usually don't have to wait longer than one hour for a support response.
They have awesome hardware for reasonable prices... i migrated everything i own from ec2 to one EX4 box with 8 cores and 16 gig of ram for less than i payed at EC2...
"If you get an Answer you don't like, probably you asked the wrong question"
As someone stated in the comments. Wordpress isn't the solution to all. Mainly it's a blogging system with the possibilities to add some static content. Of course there are many plugins which enrich the wordpress expirience but a blogging system stays a blogging system at heart.
If you speak words like
* Document Management
* Workflow Management or
* Digital Asset Management
It's most likely you misunderstood Wordpress and it's capabilities from begin.
I personally use Wordpress for many purposes private and for professional work. But if the client's demands are to high i switch instantly to better suiting solutions (which does not mean that wordpress is bad but probably not suitable for all use-cases) which makes the client even happier.
About selling the right thing:
If you go to the customer and tell him "This one-shot solution will be Wordpress and you can do everything with it !" You already oversold it and probably you should speak with your business development guys ;)
One point i agree is the release schedule, which creates quite a lot of work trying to stay up to date with every wordpress instance you have. But i never saw the so called "perfect solution" not in OpenSource and not in "I pay fricken lot money for licences"-Software.
