I think you should get the faster one. Internet speed is very important in online business job, your possible clients also recommended to have the faster internet connection for faster transmission of documents. Some of the clients also needs to talk to you about the details of your job via video call, and I think it's awkward to talk to your clients or boss with the on/off video call, and also what if there's an important e-mails to answer immediately for the possible job, but because of slow connection you didn't get that job.
Well... In my point of view, the speed of the internet for these kinds of jobs is something of the utmost importance because time can - in the most of times - mean money (if you know what I mean, haha ).
If you are working online, then a high speed internet is one of the prime requirements. It will help you to enhance your work quality and at the same time it will prevent a lot of unwanted wastage of time. You will be able to improve your work efficiency. More amount of work will be done in the same time and this will increase your income correpondingly.
I work part time online. I do various kind of online work from running and managing blogs to writing for clients and posting on paid blogs and forums. I need better internet connection. sadly, internet speed is a problem here. I live in a small town and the internet connectivity is still in the child phase. The highest internet connection we can find here is 1 mbps.
Certain forum software tends to run slow on shared hosting of 20 MB of bandwidth (or less). Nonetheless, a faster internet connection might correct the problem. In other words, it might decrease loading speed from 10 seconds to 5.
If you're working online, I almost see it as essential personally.
It depends what you mean by slow though, having like a 2mbps is just poor and unworkable.
If you have 30mbps but wanted 60mbps, well if you're doing stuff like video editing, downloading, uploading and all that jazz fair enough but there comes a point when it can just be a money sink and overkill if you ask me. Some would disagree though and say that the faster the better regardless.
If price wasn't a factor then yea faster is always better (obviously) but I can do all my daily work tasks on 30mbps and not feel 'hindered' by that speed, so I'm not gonna pay $$$ extra to double that speed if I were given the option.