There's lots of changes to Nop under the covers: - the card products are a new type of product with a new dynamic pricing scheme - there are custom (UK) shipping, payment and tax providers - there's UK address integration - postcode lookup - there's quite a few new category templates - e.g. http://www.flex-e-card.com/Shop/Category/57-south-east.aspx, http://www.flex-e-card.com/Shop/Category/93-festival-place.aspx and http://www.flex-e-card.com/Shop/Category/55-all-cards.aspx - there's lots of custom admin and shipping functions (barcodes and label printer integration) - there's a whole sub-theming thing going on for subdomains - e.g. for http://manchesterarndale.flex-e-card.com/Shop/ (still some CSS to tidy up here!) and http://cribbs.flex-e-card.com - there's a built-in advert management system - I've put some SQL transaction support in - just in case something goes wrong while ordering or shipping
All in all I've enjoyed the base that nop has given us - good to have 100% source code at our base.
It seems to work well - and we like the subdomain naming approach.
If you are using https for credit card pages, then there are additional costs for wildcard SSL domains to consider.
The subtheming is currently done by using a combination of a static barebones theme along with a dynamically generated CSS (based on a colour scheme entered into the Category) - this means the designers can now keep adding colour schemes real quick - e.g. http://lakeside.flex-e-card.com added today.
For the printers we used vbscript (yuk!) within Internet Explorer to interact with specific ActiveX objects for each printer (one bar code printer, one address printer, one invoice printer)
For the barcode scanner, we used some jquery javascript to collect text - the text was input by the scanner - it had a text input mode.