Thanks for all your comments. A wide range of views!
I am a somewhat infrequent hobbiest, getting out to the shed no more than 4 or 5 hours a week, normally. So I might cut steel once a week and I would cut big steel once a month or less.
I've discovered (as samsaranda has) that the broken chop saw came from Lidl and not Aldi – an easy mistake to make!
I've found the service department for lidl and an email address, so first I will try and get the item repaired or replaced before investing in a replacement.
Having said that…
Firstly, my shed is small and full. The cut off saws work well because they are small. I'm not sure that I could fit a bandsaw on a stand in. In fact even the rage 255SMS (which started this) is probably a bit on the big side.
Secondly, I just don't have the budget. the cost of a Bandsaw would require negotiation with SWMBO and I don't think that would go well. Of the options I've found I would probably most like the Femi SN105XL, which is the priciest of my options (of course). The AMA1140 from Amadeal is also attractive (having nearly twice the power).
The cheapest I've found is the H80 from Chester at £187.
In terms of my original question, I think I would summarise it as follows:-
The Rage saws will cut solid metal (not stainless I gather). They are known to cut significantly larger sizes than are specified and to do it reasonably well. The blade will wear quicker of course and it's unlikely to be a happy bunny if you cut 4 inch solid section day in day out.
Iain