Oh I stand corrected then. For whatever reason I thought we are talking about cash bonds. In any case, I think the request for inquiry based trading systems are going to eventually go away. Already seeing a fair amt of interest in introducing limit book type of execution tools to the buy side.
Quote from Martinghoul:
True dat and butterflies in cash bonds are perfectly doable, albeit not on a h-f basis (since I am more EUR focused it's more MTS than TradeWeb for me, although both are poor these days). For some reason, I thought the OP was referring to bond futures, rather than bonds.