The larger one just seems a little pixely and blurry in some spots. and the black line is a little too demanding in that one. The smaller one looks fine though haha. I would also make the heart just a tad bit brighter, obviously not super bright but just a little more to give it that sort of glass/glossy look you were going for. I mean you have a light source coming for the "inside"? idk just my opinion. Goodwork otherwise.
Open it up in photoshop, grab the pentool and fill out the white gradient on the heart. Should help to fix the aliasing problem you have there. Otherwise it's a pretty sexy logo thing you got going on.