I don't think that's true even for graphite. I'd never take my 11 foot 7 wt steelhead rod on a rhodo covered small stream, though I may take it to the D. I'd never take my 6-7 ft brookie rod to the D.
Anyway, the only boo I own is a dream catcher, so I don't have a huge wealth of experience, but I have cast a number of boo rods that aren't mine. Mines an 8.5 foot 5 wt. It's reasonably fast, not a noodle like many cane tapers. I can't really bomb it like a graphite stick but it's fine out to 50+ ft. It's not great in real close either, but good at 15+. So, a medium sized stream rod, which covers most situations, and I like it a lot for those situations. Probably my most heavily used rod. It's also not cheap, it was over a grand, which I wouldn't have pulled the trigger on my own but it was a gift. But that's not to say there aren't perfectly usable sticks for far less.
Taper means everything. I'd tell you that coming from graphite, boo has a MUCH higher range of actions. Not all are noodle slow, but some are, and slow boo is much slower than slow graphite. Some are also broomstick fast. And both may be labeled 8 ft 5 wt. So there's some shopping around to do. Start casting a few and the differences will wow you, and you'll start to feel like all graphite feels the same. Because of huge differences from rod to rod, and less versatility per rod, there's more of a tendency for rods to be special purpose type rods. You get a midge and trico rod, a big dry fly rod, a streamer rod, a nymph rod, etc. But many claim boo is better for those purposes. I think it's true, to a point. There are some things I think boo is better at, but others where its definitely not.
