I had the exact same struggle and considered the exact same things.
I really struggled with the idea to give up my little "tank" storage space. I have my disk locks, tire emergency repair kit, wet tissues etc. in there. Yes I can get a top case, but that destroys the great looks of my SR and I am also a leg swinger (when getting on the bike, I swing my leg over the end of the seat, like getting on a horse) which is impacted by a case.
I also find the charge tank-upgrade to not really be powerful enough, but I much liked the idea of having a Zero supported and dealer installed solution instead of something without dealer support and warranty (like Diginow type of solutions).
The SR/F crossed my mind, but after giving that one a spin, I did not feel it would be a significant enough upgrade for the rather steep investment (wanted minimum 6KW charging capacity). I actually like the handling of my SR a bit better, but I would love the new things that the SR/F brings to the table (i.e. new dash and remote updates). The fact that it does not (yet?) have DC charge options however feels to me like upgrading to something that is already out of date.
I considered an Energica for it's DC charging possibility, but I love all the Zero things like no fluids and no chain to much to give up on that. Also in my mind Energica's are expensive, there are far less dealers and the ones which are there are brand new and have no experience with motorbikes and (in my case) are to far from my home which is inconvenient for service (which Energica's need more than Zero's) and Energica's weight much more than the Zeros.
It is not a done deal in my head yet and still Energica (especially the Ego) crosses my mind regularly when thinking of a possible next bike.
So I decided to go for a Diginow 9.9Kw in a belly ban set-up. It saves my precious storage space, does not really change the looks of the bike (the pan is mostly similar to the original) and provides a LOT of charging power.
It is not a perfect choice; there is no company supporting it, it is crazy expensive, you need to install it yourself and pray it will just work and if it does work, pray it will continue to do so.
I got the install done, but I took my time to really understand upfront how everything worked, what is what and how it should be installed, where the cables should be routed to and through etc.. It took me weeks of thinking, considering and asking others questions and even then while installing I had to change my plans a few times.
Now it is on the bike, but not yet nicely finished; the inlet (plug) is still ty-rapped to the bike and the switches are not yet in their final place.
Why? 1. I just finished the first install two weeks ago and I am still testing. 2. While testing I encountered some challenges that I want to fix first before I finish up everything nicely.
I have a NEW version 3 set which does not connect to the bike's CANBAN, which should be a good thing, because that was considered to be creating problems with the 2.5 version, but it also does not have bluetooth and does not use the charging stations' pilot signal.
This means that some charging stations reject to charge and that home chargers that are set to i.e. charge at 10Amps (i.e. because there are other devices connected to the same power group) will error out and I have not option to do something about that.
Morgan, one of the Diginow owners has been super helpful on my Diginow journey. He has been answering all my questions and also because of that I have learned a lot about EV charging.
Diginow has also offered to build a brain/controller box V3.1 which does follow the charge stations pilot signal. That is great and would probably make this set-up exactly what I hoped for it to be, but my mind is stuck on the fact that I payed BIG $$$$ for something that works great, but not in all circumstances and in order to fix that I again have to cough up $$.
Also the fact that it is again not sure that it will work (Diginow is in the US) keeps me from going that direction, at least for now. I am also talking to someone else who might have an alternative that sounds really great that I want to explore first.
For all the charge stations at which it does work (which is the majority at the moment), it is really great and I just love seeing my Zero charging at 9KW+ rates and have charge times way below 1.5 hours instead of above 8 hours.
One thing that is a bit of a challenge is the fact that with fast charging, fat cables and plugs come along. Where the stock charge cable and a charge station adapter (mennekes to shuko) did fit in my "tank" storage space, the new cable does not at all........
For me there is no perfect solution at the moment, but (when I fix the final hurdle) the Diginow set-up comes closest I think, also considering the fact that when I ride and charge I rather do that at places which typically have AC charge stations, where the DC charge stations are mostly at the highways that I prefer to avoid as much as possible. That could change when changing my riding habits, i.e. I have been using the bike for commuting for a while and that was mostly highways........
The perfect solution for me would probably be an SR/F type of bike that is better protected against water, has gone on a diet but would remain to have a 12Kw AC combined with a DC fast charge option (more than 1C) and still have space left somewhere on the bike for a charge cable, two locks, some tissues and a tire repair kit.....