So here are my impressions of the Solo after 6 months of use:
My unit is a M102 model, with the silver casing. One stem is loose fitting, the other very tight. The tight one can not be got in or out when the unit is cold, but goes in quite easily when warmed up; the crucible entrance expands when heated more than the glass pipe.
I have had none of the problems that some people have experienced. Ironic really, because as a combuster I had a pretty high tolerance for poisonous fumes and would probably not have cared about a bit of flaking or smell. A high-pitched noise I would have hated, but mine is completely silent.
I get eight 12 minute cycles out of the batteries, running at temperature 5. That runs it down to the bottom light, but I have never actually run it flat so it might well do a couple more cycles. In practise, the charger mostly keeps up with my rate of use, as long as I remember to plug it in. Finding that I am fairly likely to forget to plug in the charger, I recently bought the power supply as well.
The use of some sort of filter is needed to avoid inhaling small amounts of plant matter. I used stainless steel mesh at first, which worked OK, but was fiddly; I had to cut and bend filters to fit, and I found they fairly soon clogged up with fine dust and baked on residue. I now use a tiny wisp of cotton wool, formed into a thin disc. This works well and can be discarded and replaced after a few bowls when it begins to clog up.
For any combusters lurking out there as I did, I highly recommend the Solo as an introduction to vaping. It does not need a lot of maintenance; the only part which needs regular cleaning is the glass tube, which is not difficult. Mainly, it is very easy to use it effectively and efficiently. Right from day one, my consumption dropped by half, without loss of effect. This was very encouraging, and meant the unit soon paid for itself. I have since bought a VaporGenie for emergency use, and while it is fine for its low price, it needs more technique to use effectively. I am glad I got the Solo first, because it showed me straight away that vaping is the way to go, FC!
Thanks to all the good folk on this site, who provided me with the encouragement to go vape and the information to make what I still think was the right choice for my purposes. Now that I have Read The Whole Thread, I feel qualified to maybe make the occasional comment.
Finally, I should put in a word for AustralianVaporizers.com.au ; discreet packaging, top service and incredible speed.