Joined: 10 October 2007
Have a chat with some technical staff agencies, I am sure they will advise you what empoyers are likely to be looking for and who they already have on their books, i.e., your competition.
HNC was originally put together for people to complete part time over two years in which time they would be expected to be working and gaining practical experience. ONC was much the same. The diploma courses we/are full time and thus provide aspects which compensate for the lack of experience. It is not always exactly like this but that is the basic idea.
By the time you would have finished the HNC the economies could be better or worse and so you should only take today's advice as a guide. If you do a part time HNC and do not give up your full time job then of course you have nothing to lose but the monies spent on your studies. But if you like engineering then that will not be a waste and if you chose correctly it could also represent the first year of degree/HND study should you then decide to study full time.