Having to remove the stem between hits is very cumbersome (as you are flirting with a delicate glass piece each time) and not at all how the device was designed to be used. Having to turn the device up to a higher temperature to achieve the same instant results that the TV gives painlessly betrays your own sentiment that 3 to 4 is the sweet spot. At 3 to 4, the stem does indeed need to be left in in order to do the job of producing vapor and spending the load in an expedient fashion - which then leads to the stale, musty taste that you and I both agree exists under these conditions (as it was designed to be used).
Even the very first hit off my Solo is "musty". I disagree that the Solo can be run just for the first 3 or 4 hits and then dump the abv and call it a wash with a TV. The first hit off the TV is superior, the second hit is superior, the third hit is superior, and the fourth hit as well. That stale taste with the Solo is present from the get-go. It's the same taste I pick up on with my iolite. It is the result of low heat, applied steadily over an extended period of time (which is exactly what I would characterize the length of time that the stem must be exposed to the chamber before drawing even your very first hit: 20-30+ seconds of exposure to heat, instead 5 seconds of warm-up prime time for the TV). It's also the same principle that sets apart the Volcano (as a convection vaporizer) from its lesser competitors. The difference is the duration of exposure to heat, coupled with the intensity of the heat which the load is exposed to. Hotter for shorter period of time is better than cooler for longer period of time. Both in quality of the vapor produced, as well as the expediency with which any given amount of material is effectively "spent". Within reason, of course. Even with that principle in mind, there is a delicate balancing act between the two. Because the rate or airflow on a Volcano is a fixed variable, I do not ever turn my temp past 6.5 on the dial, or else the temperature is too high to keep up with the rate of passing air and I end up with too thick a vapor that is full of much more carcinogens, same as with a conduction vape.
My point about vegetative plant matter being roasted and thus vaporized is absolutely telltale in the abv itself, as I mentioned previously. The TV, by its very nature, exposes hot air to the material for a very short period of time. This, by the laws of physics, dictates that only the most volatile of the oils remaining on the plant matter will be vaporized with each fleeting pass of the hot air over the material. By comparison, a Solo sits there and "cooks" the entire load (as it was designed to be used). If you're getting better results by removing the stem in between hits, kudos to your mod. However, it sounds like that manner of use stands to both severely lessen the battery runtime (due to the need to have a higher temperature, as you said) and its convenience of use without having to stir or remove anything between hits (two of its nominal advantages over the T1). Ultimately, you're still coming up short of achieving that same rapid ramp up of heat to the load that the TV excels at.
I'm not trying to make any assumptions. I am a hands-on user of both products, and I find your points about how the Solo overcomes its inherent hurdles to be revealing. True that the abv of the T1 is uneven, unless stirred between hits. This is because that intense heat is so near to the load, that the bottom portion of the load is exposed to a more direct (yes conductive) heat than is the top. The key here is that it is for an extremely short duration (not unlike the Volcano, which also requires stirring the chamber for more evenly-spent abv, though I concede the Volcano does not ever run the risk of charring the bottom as the TV does on rare occasion; though only if you don't take the palliative clues and accordingly pulse the switch). So, not having to stir is not necessarily the mark of a good vaporizer, you see. And FWIW, I definitely prefer the consistency of taste and vapor quality with my T1 as compared to the EVO, for example. I feel any vaporizer that does not conveniently allow the load to be stirred in between hits will ultimately not perform as well. The easier the load can be stirred, obviously, the better. Maybe down the road, TV will develop a cap for their device (or a future device) that integrates some spikes for the purpose of stirring the load with the cap on, as has been previously suggested a few pages back in this thread. Implementing a stirring device into the chamber would be a welcomed addition. Though, I am sure there are complications that make it more easily said than done. I can envision it being more difficult to blow the cap clean of debris around the airholes, for example, if there were a jagged stirring device impeding the ability to wipe clean the top of the cap while it is warm and then blowing it free of any remaining debris, as is now my practice.
Very cool. I too had a hard time looking past her prissy take on inhaling what was a relatively tiny cloud of nicotine juice. And that's even with me being able to relate, seeing as I do not imbibe in the juice myself.
edt: Sorry for the long response. Please note that I did go back and change a few details of my original post in the interest of factual accuracy. My apologies for any initial confusion, and for the possible need to re-read this post to understand what I corrected myself on.