I can’t give any advice as to the ‘smoothness’ or otherwise of such a transfer, in theory, at least both systems use the same infrastructure, the business accounts use a hitron hub rather than the domestic hub 3 or 4 but they are broadly the same. There can sometimes be problems if you have opted for the static IP address provision because of the way this is provided.
As far as I know, through, the biggest drawback is that I believe that you can’t have TV on the business package not does it allow any email provision, so you will lose any email addresses you currently have. Of course, you may well already be aware of this and it isn’t a problem for you, but I have seen one of two posts by people who have moved to business and didn’t realise, or it wasn’t properly explained to them, that they would lose their email and it came as a bit of a shock!