I've got Ibby SR 506, 1206 and 1006 (though the 1006 is now sold awaiting collection). The 506 is good value, after a lifetime of Fenders, but the 1206 (current model is 1306) is definitely better, much punchier pick ups. This year the 1206 will be my main bass, with the 506 as back up.
I don't use the C string for chords, but to save dashing up the dusty end to reach high A, etc, which the C string brings down to the 'safe' area below the twelfth fret I find I am playing across the board much more than I used to, and playing up and down it much less, which in my view helps with accuracy when playing on stage as everything you need is likely to fall under the fingers without having to move more than a fret or two up or down the neck. I'm just getting lazy!