I’ve been waiting for something like Thermawing and hope they will STC as many legacy airplanes as possible. Makes a lot more sense than boots or TKS to simply heat the surfaces affected so that no ice can form in the first place. Anti Ice is always better than De-Ice.
I’ve only flown boot equipped planes before, Piper Seneca as well as Baron. They work great and I would prefer boots to TKS for the simple fact that they do not need refilling and don’t produce corrosive materials which needs cleaning and care. The Senecas I used to fly had their original boots which were cared for regularly with some sort of treatment agent. Too long ago to remember what it was but probably something like this: Link
worked really well. We never had any boots fail or even leak while I remember.
Having said that: Looking at the price of the SEP Planes in discussion here with TKS, why not consider a less costly alternative with proven ice protection like a Seneca II or the likes? They are to be found a half the price Jason is looking for and add a good amout of safety in terms of the 2nd engine and proper FIKI protection. The savings in purchase with a budget of 200k would leave substantial reserves for flying and maintenance. Several people I knew looking for a high end single eventually did exactly that. One bought a Seneca, another a Cessna 310 and a third a Turbo Twin Commanche (which is my secret dream twin but not FIKI approved unfortunately, jet some are de-iced).
If I ever felt the need to upgrade, that is what I’d do. Get a reasonably priced Seneca II with LR tanks and full FIKI as well as half time engines for 50-80k € or something similar. The rating is feasible, no big deal there, but the added safety for night and overwater flying is not comparable to anything a Single can do, no matter how well it is ice protected.
My Commander 114TC has TKS and it works well. However I use it mainly to stay out of trouble or to get out oftrouble.
Full tank is about 67 lbs.
Be aware with th SR22. Only in 2009 did Cirrus launch a FIKI certified SR22. All SR22 from before may have tks but they are not certified.
To have a truly certified system the weight penalty is not only the system and fluid but also a second alternator! The speed penalty is indeed something like 2-3 kts.
I wish that the SMA engines were available for the Seneca. That would be the ultimate GA aircraft.
Yes, there’s two TKS versions for the SR22, normal and FIKI. But all SR22s have 2 alternators, and batteries
Re boots: The most neglected maintenance for boots is renewing the conductive edge sealer which should be stripped and re-applied every few years, if not, the boots get trashed by blow holes.
A Piper Matrix has boots – I was trying to recall if there were any other SEPs with boots?
Some of the big old Cessnas have boots.
I am surprised at the short life of boots. I have seen many of the planes under maintenance and I would say that in all cases they were repaired or replaced only when they had punctures. All the time they held the air, they were left on the wing. Hence the fact that boots are lifed is news to me!
But then we aren’t going to get many of those owners saying they haven’t replaced theirs in 20 years, are we 
Thermawing is nothing like jet bleed air anti-ice. The latter heats up the leading edge to a high temperature and the water vapourises upon impact, and in any case there isn’t much left of it by the time it runs off. The former is only just warm enough, so the water can run off and freeze further back.
For pure effectiveness regardless of other factors, TKS can’t be beaten…
30l of TKS will have a mass of 33kg (SG 1.1)
My experience is that you have to pre-empt icing with TKS. In other words you need to switch it on as soon as you think you will get ice and not wait until you get a visible layer. Conversely, with boots the best way to deal with icing is to get a reasonable covering before activating the boots.
As others have implied, the issue with TKS is that it is a finite resource and most of us wouldn’t be willingly spending unnecessary time in icing with only a TKS system on board; this is a significant constraint. For example, I was operating in Eastern Europe last week and on a 4:35 task was subject to icing for about 3:00 hrs. With TKS I would have had to divert or cancel the flight; boots give ‘infinite’ de-icing.
All that said, I think TKS is still a very reasonable solution to icing.
In the Cirrus (according to the POH) you have two settings: NORMAL (switch on before you enter icing conditions) and MAXIMUM which is used if there is already some ice visible. I do not know how well the latter works though
I think there is a specific reason for the low/high setting on the full TKS system, but it doesn’t apply (IMHO) usefully to the prop-only TKS system which I always set to HIGH some tens of seconds before entering freezing IMC.
