It appears the 510 is the same size as the 901, so I assume that batteries are the same, the carts are interchangeable, so the only question is - are the atomizers similar as well. I'm guessing that the 510 auto would act very similar if not exactly like the 901 .... the only difference is when you compare the 901 auto against the 510 manual and also that if all else is equal, it will be as I have surmised... that any difference people taste in loss of flavor is a result of overusing the manual button.
It's pretty simple - if the battery, atomizer and cart are the same and the only difference is in a mechanical aspect - that the 901's atty is female instead of male, like the 510 - then any difference can be attributed to the user not the ecigarette.
Kent,
You make some good points in your email, in particular the idea of not comparing apples to oranges or manuals to autos. But you have made some surmises and drawn some conclusions which are not correct.
I own both a 510 and a 901. (Both of my models are auto and my comparison(s) are of these two auto models. It is a pretty similar comparison).
I can tell you that they are about the same size, yes, but they are the product of two different but conceptually similiar designs. The 901 is the older of the two designs, the 510 is a later design.
Pictures of examples of both models exist at the new members forum in their own sticky thread,
http://www.e-cigarette-forum.com/forum/new-members-forum/17425-attention-newbies-pics-most-common-models-here.htmlbut I looked and they may not be detailed or close up enough for you to tell the difference between the 901 and 510 models easily. But there is
Lots of good info in the new members forum, I have spent a good amount of time reading through those threads to get a baseline familiarity with vaping. (That's for any junior members who happen to read this, not for you, Kent, I see you have over 1,200 posts at the moment.)
I uploaded a picture of my models next to each other with the components separated. It's a little overexposed, but it's just a cell camera, sorry. Hopefully you will be able to see some of what I'm describing.
Overall the 510 is slightly shorter in length when both are fully put together with battery, atty, and cart. The diameters measured by me as identical to the best of my ability to tell. The battery of the 510 is physically longer by perhaps two or three millimeters than the 901. The atty of the 510 is shorter by a centimeter than the 901. The full length of the 510 cart is about 2 mm longer than the 901 cart, and the part that extends from the back of the atty is about 1 mm longer on the 901. In closeup, you can easily see looking at or into their ends that the battery, atty, and cartridges are all (slightly)different designs, call them different spins on the same ideas. The atty of the 510 runs hotter than the 901 - it is heating the eLiquid hotter to vaporize it. The physical appearance of the metal wicks of the two attys is really extremely similar, and I believe from reading online they are made from the same metal composite. The wicks also have very similar lengths, shapes, and distances from the cartridge.
The battery of the 901 has a slightly lower voltage than the 510 battery. The 901 battery, however, lasts longer for most people than a 510 battery. The 901 battery connector is a short male screw thread while the 510 has a short female (like a screw nut) threaded connector so they are not readily interchangeable or compatible.
510 carts can work on 901s but they are not quite as tight, just a snug fit. I have used them successfully. I wouldn't try to put a 901 cart on a 510 atty, though. The 901 cart is too big for the 510 and might get stuck, or you might damage it or the atty in trying to separate them if you did manage to put them together.
There are additional cosmetic differences to the outsides of my models. For example, my basic white DSE901 is gloss-finished and has writing on the atty and thin light lines on the battery, while the 510 is a solid matte white it looks slightly different in finish only from the one pictured on the forum thread link I provide.
Competing companies? One company/entity with two successive models? I don't know for sure, but I think the latter from some marketing pictures of successive models I have seen online.
Do you have any links to text describing a loss of flavor in the 510 itself due to switching from auto 510 to manual 510? The only references I have heard are comparisons of the 510 to the 901. It is true that most people describing 510s seem to be using manual switches, and most 901 users are using automatics. I would prefer to see a controlled double-blind test of several models, for example, but who is going to back such a study? All we will have for the foreseeable future is I guess, subjective personal experiences, without important details like manual/auto, mods, supplier, model type (generic 510, Joy510, 901, DSE901, etc.), etc. But what we can do is try to set higher standards for ourselves as individuals when self-reporting.
Perhaps a visible profile page could be added where members could list the make, model #, mods, supplier, and other information for each model they own.
They could also have a place to list their eLiquids, prefilled cart brand, or recipe of choice.
And a checklist of their preferred vaping behaviors (inhales, sucking inhales, blowing out through nose or mouth, holding eCig in what way, time between inhales, etc.)
That might help to make some informed speculations about why some people love certain models. It could be the mix they are using, or their preferred methods of vaping, lends itself more to one model than the other.
Or maybe we could find no correlations, and could move on to other possibilities. It's not perfect, but there are things we could do besides endlessly speculate and insist on our current preferences.