I hear you, also on Ubuntu, and although the latest version of SP Flash is supposed to work on Linux, didn't figure out how that would work, I guess it's command line messing.
So I got a Windows PC from somebody, sorry but that's the easiest way.
Unfortunately, P780 (and all MTK devices), are easy to flash so everyone is using that method.
Installing from recovery is not that popular, but there are exceptions.
Most of the time, you start out from a stock version, which you have now and backup, backup, backup
that one. You'll probably need it if you want to install another ROM.
As far as I have learnt, there are a couple of ROMs you can install given that you have a stock ROM already running.
Either you stay on this forum, and you can try Life or Vibe, or you go to www.needrom.com/phone-roms/lenovo/serial-p/p780/
. Most ROMs there are recovery installable, and so suitable for your situation. So far, had no problems using ROW base with one of these.
vibeui.com (in Chinese, but apparently the 'official' Lenovo daughter site), offers Vibe 1.0 and 1.5 as recovery installable.
I've installed and played around with SLX, Vibe 1.0 and Vibe 1.5 (KitKat), all installable from recovery.
Although I tried to stay with Vibe 1.5 (because KitKat), I reverted back, mainly because:
- signal was worse than other ROMs
- I have a magnetic case working fine on stock but not at all on Vibe 1.5
- Battery drain problems, especially because of location services
- Location services not working for applications
- All in all, just a bit too buggy
SLX was the most pure Android I installed, but I missed the Lenovo specific additions.
In all honesty, I like the stock ROM after all, the Lenovo apps ans launcher, and settings are actually pretty good. I in fact like the Chinese stock rom more than the ROW (more settings, security app has more options,...), but a lot of stuff is Chinese, so no
One tip : on a stock version, install Xposed and the Gravitybox module, it's almost as good as installing another ROM. So much tweaking and modding, that I can customize whatever I want.