Wow.
Didn't think I would spark so many conflicting opinions.
Distortion/Overdrive pedals have a place ... in my case, it's in somebody else's setup. They are practical and have their purposes. If you have a Fender Twin or a JC-120, then they're almost necessary. If you have an old Marshall Major, then absolutely. But, for all intents and purposes, they exist for one reason and one reason only; to reproduce the sound of a tube amp run flat out wide open and loud as hell. They are trying to mimic the even order harmonics and compression characteristics of overdriven power tubes, used in conjunction with a moderate to heavy amount of preamp gain. This is without a doubt. I really don't believe that there is a pedal manufacturer out there who tries to recreate the sound of a "preamp gain on 10, master on 1" kind of overdrive pedal.
If we're talking about sustain, then once again, we're back to the same point. If anyone has every plugged a guitar into an amp with low volume, and then increased the volume, then naturally, sustain will increase. Once again, we're talking about a cranked tube amp. Once again, pedals try to simulate this sound. Whether it's a clean boost, or a mixture of both like the Sparkle Drive, or a straight up distortion/overdrive pedal, we're back to the same thing. Compression is a completely different beast, so it doesn't fall into the scope of this discussion.
One thing we don't know about our fellow slutz's original question is; what kind of sound is he looking for? What kind of tone is the goal here? What are the rest of the pieces of the puzzle? What kind of guitar is he using? What, if any, other pedals are in the mix?
We know that there's a Hot Rod series Blues Junior and that's it.
There are some fundamentals that we don't know about as far as what he's looking for. Hell, for all we know, he might've gone out to the local GC or whatever and bought whatever they had on sale that day and told us all to take a hike.
He could be going for a sustain forever Gimourish type of tone, and have a solid maple bolt neck guitar with lipstick tube pickups for all we know.
One thing I do know is, good tone equals volume. Good distortion comes from power tubes on meltdown. Preamp distortion is great for beginners. Distortion pedals have a place in the toolbox as far as options when dealing with a loud, clean amp. And the pedal wars will never cease. But I still love trying out distortion pedals, even if they will never find their way onto my pedalboard.
Thank you for so many different takes on this subject, and I hope the subby will answer some of the questions I've asked. I'd love to hear how he made out with chasing the tone dragon ...
Peace.