When I started diving, tables where still very much in use. this meant either the US Navy Tables, the RN Tables or the PADI tables Buhlmann tables etc.
Computers where becoming more readily available, and more reliable. The algorithms where far more aggressive then than they are now. Progressively manufactures have add additional 'safety', compensation for water temperature, profile, repeat diving etc.
The likelihood of buying a computer from the mainstream suppliers that has a bad algorithm is very low. The question is the 'flavour' you have to your taste. Decompression theory is still not very well understood, various approaches become 'flavour of the month' and then are discredited.
I can remember the Monitor II being the preferred computer for deep divers in the UK, "because it got you out of the water quicker" than the newer models coming into the market. There was a roaring trade in secondhand units for quite sometime.
The first computer that removed the padding was probably the VR3. You had to set the safety factor (it added additional perceived Nitrogen Loading (I cant remember the numbers but it was based on pro planner, say 1% Nitrogen for every 10% safety factor - don't quote me on that)). if you dived it without adding in some safety factor, you where likely to get a bend eventually.
In short, most modern dive computers are very safe, with additional padding to compensate for bad dive practice. The only computers that really buck this trend are those for the technical market, which assume you understand what you are doing, and the related risks. In some you can even download your own decompression algorithm!
What normally happens with new divers is they either buy what the instructor is using, buy what their circle of divers are using (in a club), or buy what's on special offer.
In my opinion it is often best to use what your circle of divers is using, much easier for dive planning and conduct. Help when learning about the functions and functionality.
If it ever becomes a significant issue, the new diver has gone hard core, is better educated and is upgrading their kit anyway. A Shearwater Petrel or OSTC2 is not really suited for 90% of the newly qualified divers coming into the market.
Gareth
PS - The Suunto should be fine, for my recreational diving I still dive on a Vyper, I used to use both a Vyper and Vytec - until I flooded the Vytec
.