Hi Jonny,
I like querying via QM as I like the structure. However, while I have not compiled the stats (and they would be subject to the vagaries of small sample size anyhow), I get the feeling that I receive a greater proportion of fast declines via QM. In fact, I think all eleven of my requests for submission have come via email queries and responses.
Another reason I prefer email querying is that it gives me a chance to try to turn a decline into an R&R, which I have been fortunate enough to have done twice now via email correspondence with the agent. In contrast, when an agent replies via QM, the email always notes not to reply the response will go to an unmonitored email.
Still, I like the quickness of submitting and hearing back, even if they involve rejections. As you alluded to in another chat group, closure is good even if it's not a favorable outcome. It's like when you're dating...much better to know the girl has truly broken up with you rather than just fading out and leaving you hanging...
RCL