Actually not a dumb question at all, quite astute in fact and one I suspect many turners ask repeatedly. The short answer is probably no! However that has some basic assumptions which is that the steel is more or less the same (obviously I'm talking about HSS here).
Lets just park the steel issue for a moment and focus on the others. The two big areas of difference are the handle design and the profile. So take a gouge for example, some makers will have a deeper flute in their bowl gouge than others and that's about personal preference. Longer handles are better for work where the tool is a long way over the rest as you need to extra leverage at the back to counter the tendency to catch. This is especially true with scrapers for doing the wall to base transition in deep bowls or tall spindle turned hollow vessels. Also, the aesthetic of the handle, the wood used and how it fits in your hand/arm are considerations. Personally I like Sorby's design but then I don't like their prices and I cant tell any difference in the performance of their HSS against a cheapie Axy low range tool. By which I mean they both seem to hold a freshly sharpened edge about the same time. There are many other such details about profile differences, rounded sides on a skew is another example. Again, I roll beads using a skew so I like a skew with rounded edges. I have square edged skews too from my Dads old turning tools and I soften the edges on those with a grinder.
I've arrived at the conclusion that most of the HSS is pretty much the same and therefore the choice lies in the details of the profile and handle design. I've now started buying Ashley Isles metal only HSS ie unhandled tools and then making my own handles from Ash (I have a lot of Ash due to a storm damaged tree in my garden). Two reasons, they're cheaper that way and I like longer handles so I get the tool I want at the end for less cost. Having said that, I must have 30 or so tools from the last 4 years from just about everybody so its taken me a while to hone my ideas about what works for me.
So to summarise, I'm not convinced there is much to choose between HSS made cheaply in China and that in a top of the range Robert Sorby tool and in fact I wouldn't be remotely surprised to learn they both come from the same Chinese foundry! But there may be differences, I just don't know. When I've used tools from different makers, they all hold an edge and the only big difference I ever notice is between older carbon steel tools and HSS. Carbon steel tools definitely blunt much faster (but they can be sharpened to a finer edge too, it just doesn't last as long as the harder HSS). Because I don't value the differences in the steels, my basis for deciding has now become the handles and profiles. Because few off the shelf tools have longer handles, I now buy tool steel "naked" and make my own handles, saving money into the bargain.
