I've never used a Delta but they had a good reputation as an introductory/intermediate level saw. The blade clamps made changing blades a speedy doddle. I think Black & Decker now has the rights to the Delta brand but I may be mistaken - there seem to have been a lot of corporate takeovers over the last couple of years and it's hard to remain current. Whatever, they're being built in the Far East and the quality has suffered. There are still a lot of older, quality Deltas around which can often be acquired very inexpensively. Oh, and if you ever come across a saw with the Fox brand, it's also a Delta which was aimed at the European mainland market whilst production was being transferred from North America to Asia.
What's the difference between a Diamond and a Hegner? Diamonds are bigger, heavier, noisier, have rotating blade clamps, can be slowed down to the point of practically no strokes at all, and they have a more pronounced back-and-forth cutting action which makes them more aggressive. They are also effectively obsolete because their manufacturer is no more, although anyone with an aptitude for mechanics should be able to maintain them for a number of years. There are a few other differences too (such as Diamonds having plywood tables) but I think I've covered the main points.
The old Deltas were never in the same league as Hegners and Diamonds but they were certainly a fine saw.
