I have Quickload and recently spent a whole day playing with it. It tracks pretty good with most bottle neck rifle loads out of reloading manuals but there were some major differences on some cartridges. They warn you about straight wall cases such as the 45-70 and rightfully so. The data wasn't anywhere close to published data.. I've been reloading for a lot of years and can guess better than Quickload on most cartridges. Personally, I think it's a waste of money and a good way to get in trouble. Because all loads are "calculated" they don't take all parameters into account. I would recommend using a good reloading manual (or two, or three) before trusting the calculations.
I have Sierra software, which is identical to their paper manual only on CD. It's easier to locate a given cartridge and you can graph the predicted results. Of course, it only lists loads using Sierra bullets.
One software program I can highly recommend is Ballistic Explorer (by Oehler Chronograph). It does not list any reload data but does have the best exterior ballistics information available. It will graph charts on just about any parameter such as, bullet path, bullet drop, velocity, energy, wind drift, and is extremely accurate. The program has a built-in database of factory loads that I find very valuable. Not only does it include modern ammo, it also has data for discontinued cartridges that are rarely found in manuals. The factory data includes all case measurements, bullet style, weight, coefficients, and muzzle velocities. After you reload for a while, you finally figure out that loading to factory velocities and bullet weights almost always produces the best results.
The good thing about using quality reloading manuals, the companies such as Speer, Hornady, Sierra, and Lyman, actually test their loads. Some are pretty conservative but that's OK, it keeps you from doing dumb things. The manuals also warn you about certain makes of guns, overall lengths, case capacities, preferred primers, and other general information that is not considered in Quickload.