I'll throw in my 2 cents. I went on the rabbit trail of trying to find a little more grit to my tone. I tried the Boss OBD-3, and put it on Craigslist 3 days later. It didn't do what I wanted. Then I ordered a Sansamp BDDI. Came in, plugged it up, and I instantly loved the dirt grit that it added to my tone. It gave a little boost to my EQ that brought out certain aspects that I really dug.
My drummer at the time also mentioned that he heard me a little more clear after I got the pedal.
These guys are right. It won't make crap gear sound like a million bucks. But it will add an edge that I think you'll like. Some people are suggesting to just save your money and get better gear (i.e.- spend more money than you're planning later instead of a little now). My opinion, get the Sansamp, and then get new gear later. Even with a good rig, you still might find that the Sansamp is useful. You can use it to DI your chain later if you don't find yourself using it for tone.
My current gear is (well was) a Sansamp RBI (rack unit, same as pedal but with an XLR level and a mid control), into a Gallien Krueger 1001rbii. For several years, this was my tone. Then I found the MXR DI. It's got a clean boost and a distortion that the Sansamp doesn't. I find myself still using the Sansamp with the clean boost of the MXR pedal.
Fast forward to now, I've actually built a pedal board to get my tone now. And I'm planning on getting rid of my rack with the Sansamp. I've upgraded the Sansamp to a Darkglass B7K for most of my EQ and tone (I'd HIGHLY suggest this pedal instead, but it's nearly $400 new). So the chain goes MXR compressor->tuner->phaser->B7K->Wah->MXR DI, that in turn goes to my rack which is the Sansamp->GK amp.
I find myself liking certain combinations of B7K, MXR DI clean boost and Sansamp combined. I still haven't tinkered with it enough at a high enough practice volume to know what I want, but I wouldn't hesitate to swap my Sansamp rack unit for a pedal unit and possibly throw it in my chain later.
Cliff notes: I think you should get the Sansamp. I don't think you'll be disappointed. If you don't like it, you can probably sell it for nearly what you paid for it. And there's a good chance that you'll still use it down the road, even if it's just for a DI.
Just my opinion and my experience.