Hi Nicolas,
Thank you for the reply.
In this case the template over-ride was one I wrote myself ( along with additional css ) to get a very specific layout, and personally I find the over ride system is generally a much simpler way of doing things than writing plug-ins or odd bits of php code, and simpler for anyone who has to work on the site after me to understand as it's a universally standard way of doing things.
If this had been a live site in which, after a seemingly insignificant update, all the products disappeared I and my client would have been very unhappy. I do take backups just before doing updates but it takes a while to restore them and then it took me a couple of hours to figure out what was going on. I just don't need that kind of hassle and it puts me in fear every time I install a Hikashop update, so my plea to you is, please stick to the accepted way of doing things and don't put potential site breakers in templates!
Many thanks,
Ian