I didn't like the Ashdown J-Lo and couldn't get a good sound out of it - and had similar experiences with the Owen Gremlin and Markbass Distorsore, which work in a similar way. Main problem with it is that the distortion channel has no low end, so you blend it with the clean you end up with less bass than your clean bypass sound. Plenty seem to love it though, and it's cheap!
If you want a bit of throaty roar with a mid boost, a Bad Monkey modded for a little extra low end gives you the best bang for buck I reckon. If you want more of a clanky grindy mid scooped tone, the Sansamp VT, BDDI or the Behringer BDI21 knockoff are the way to go. These 2 pedals play very nicely with each other also so why not get both!