I don't know. CDspeed is a powerful tool for "power" users, but it's not the most user friendly application. If you didn't see any errors you can probably assume it's okay.
I guess one advantage of Nero is it can verify the burn. I don't know any other way to verify an image burn. I'm not even sure Nero can verify it, but I think it claims to. Well maybe there is a way. You could use a program that copies a DVD/CD by making a .iso file on your hard drive and compare it with the original. Nero can do it, but I don't know if you can get it to make an .iso file. It prefers to make it's own variant. .nrz file, or something like that.
I just burned the "Ultimate Boot CD for Windows" to a mini DVD and it took one minute and 32 seconds. Here's what it shows. Now you know why I don't use CDs. DVDs are faster. They boot faster too.
I've noticed the .iso files on hard disk are much bigger than the actual burn. In this case the .iso file I burned was over 1 GB on the hard drive.