The comet you remember is the spectacular Comet Bennet 1970 II, visible during the predawn hours of the spring of 1970. Comet Hyakutake had a bluish gas tail, which was straight and faint. The type II tail is due to dust and is usually a faint yellow in colour due to reflected sunlight.
Dust tails are usually better defined and at their best are much more spectacular.
Comet Hale-Bopp should be slightly brighter than Comet Bennet at its best when it reaches maximum brightness at the end of March. The curvature of the tail happens for a fairly straightforward reason. As bits of dust come off the nucleus, you'll find that some are moving faster than others. As the particles get blown backwards by the pressure of sunlight to form the tail, the faster ones will move further out from the sun then slow down, while the dust particles that are initially slow will fall closer to the sun and then speed up. The gradual separation of the slow and fast moving dust particles into different orbits makes it look like the tail is curving.