I have a C33 and until recently carried it in a Lower Adventura 170, which accommodated the camera with an 80mm lens just fine. Also with pockets for spare film, lens cloth, small notepad and cable shutter release. This was a snug but adequate fit. More recently I've been using a 180mm lens and L grip. The Lowerpro can just about manage the bigger lens but I had to keep detaching the grip to slip the camera into the bag. On a walkaround, therefore, I had to choose between keeping the camera on my neck strap with the grip - a heavy combination - or in the bag without the grip - a nuisance. The camera fits the Lowepro but its rather cramped, if reasonably cushioned.
I've recently purchased a Domke F3-X Rugged Ware bag. It's perfect for the TLR, with plenty of space for the previously mentioned incidentals plus my handheld light meter (I've stopped used my gossen lunapro but even this will fit comfortably), water bottle and a little more. My travel tripod (Velbon 53) won't fit in with the camera but can 'stand proud' in a side pocket if necessary (not tried this in the field). That's not ideal and I'm sure I can identify a workaround for short, specific excursions that attaches the tripod to the outside of the bag. I'd rather work on this problem than commit to a larger bag. The Domke functions really well as a day bag with or without the camera - I never feel as if I'm carrying luggage. Bringing the camera into use out of the Domke is much easier than trying to do this with the smaller Lowepro. The bag isn't as well padded but I like its unstructured nature and I can add padding if I want to.