The question about the ASP.NET hosting location is very popular, what hosting is the right to choose UK or USA hosting?
Bellow you will find the main advantages and disadvantages of both locations:

UK ASP.NET Hosting

1. If your customers are Europe or UK based then the ASP.NET hosting is the right choice for you, because the response time will be better and your sites will load faster in UK.
2. You will have an UK based customer support and local phone numbers, so to resolve faster your issues.
3. The hosting prices will be in GBP, so they could be higher than prices in US.
4. There should be no difference in the provided hosting technologies, so this should be not an issue for you no matter what is your choice.
5. The hosting location could help you regarding the Search Engine Optimization, so if your hosting company is UK based then your site will be better indexed for UK locations.

USA ASP.NET Hosting

1. If your customers are Europe or USA based then the ASP.NET hosting in US is the right choice for you, because the response time will be better and your sites will load faster in USA.
2. You will have an US based customer support and local phone numbers, so to resolve faster your issues.
3. The hosting prices will be in USD, so they could be lower than prices in UK.
4. Sometimes the US based hosts provide faster the new technologies as the new ASP.NET or MS SQL server versions.
5. Your site should be better indexed for US based locations.