[justatech]

While we are worried that performance may be lower and costs higher - we are not sure if this would be the case. If we can get the same performance for a comparable cost (say within 10 to 15%) of what we are currently paying, we would prefer EC2 for two reasons 1) Redundancy - in case we have a problem it would be easy to restore instances and be back up online quickly 2) Flexibility - as we occasionally (2 or 3 times a year) do have peak traffic loads when we could use more servers.

[Travis]

A hybridized approach may work for you in those higher periods. Depending on your bottlenecks, it may be possible to spin up ec2 instances during your high load periods that will cover your necessary additional capacity. (Esp if you are bw or RAM limited, you can setup asset servers on ec2 and just change DNS pointers to enable them.)

One other advantage is your future scalability, as well: as your site grows, you'll need to "resize" your dedicated instances. If that is something you need, then that's another advantage (really, it's continuous ability to scale versus discrete scaling events, e.g. upgrading a dedi server).

That said, if you have a good dedi provider, upgrading those shouldn't be too tough.

[benologist]

Flexibility is the only major reason to go with them, redundancy's easy enough to achieve with additional servers.

I don't know if the price would be within 10 - 15 percent, you're really paying a premium and across multiple billing streams, very easy for it to be a lot more expensive than that.