A few months ago, I wrote about the benefits of getting a direct connection to the cloud. If you're considering heavy usage of public cloud services (especially IaaS and hybrid IaaS), having a direct connection onto your cloud service provider's network can make an enormous difference to the user experience. This is especially true for latency-sensitive applications, such as server-based computing (Terminal Services and Citrix VDI), and bandwidth-hungry use cases, such as data replication and cloud backup.
While you might be able to justify the cost -- or even show a savings -- of having a dedicated, high-bandwidth connection to a cloud service provider when running a large infrastructure, smaller businesses are much less likely to be able to make that math work. Instead, like the bulk of cloud users, most small businesses are forced to use commodity Internet access to reach resources they've decided to move into the cloud.
This may not be so bad if you have access to cheap, high-quality bandwidth or if your use case isn't particularly latency- or bandwidth-sensitive (Web-based SaaS applications like Salesforce.com might fall into this category). If you're not so lucky, it's difficult to know ahead of time how your user experience will be impacted. The surest way to know is to try it, and thankfully, many cloud providers will give you a trial run of their services so that you can do so. Unfortunately, if you want an accurate answer, "trying it" could mean migrating entire on-premise applications into the cloud -- a time-consuming process.