Support Team is clearly an asset for SI at he same level than the quality of your product.

For a French-speaking as I am, without no experience of Joomla plateform, the quality of the support is a go/no-go decision to buy your product.
With 7h gap and mainly the week-end, I am always stunned to receive answers so quickly.

Do not change anything and you will have customer for years.

BR
Henri