I've done it a few times and unless you have absolutely zero (indoor) conditions it's horrible. Even the slightest of air movement and it's not worth it.
I will either fly a standard 1.5 on short lines or (more likely) turn to single line gliders.
If rev came up with a 1.5 size that fit in between the standard and indoor and could take the sand and concrete, I think everyone would want one
I'm also a 30' guy ... like JB said, big enough to fly shapes or patterns, but short enough to get the job done.
My exception (space not withstanding) is that horrible circumstance where the 'wind' is constantly shifting directions (usually breathing back and forth with gusts from random directions in between) and I need to be able to do a 180 (horizontal or up and over) in a heartbeat because I'm suddenly on the wrong side of the window. In this case I am currently developing my skills on 12' lines, but my intention is to be able to stretch back out to 30' lines.
The two instances where I think 12' works are near zero wind (check Youtube for JB rev'ing it in Singapore) and/or when you interact with the environment to make it interesting (check Youtube for JB in the UK).
A good contrast can be seen in Watty's 'Friendly Neighbourhood Street Flyer' video
The 1.5 is the better all around platform and where I spend 90% of my time, but the fun of the 2 is often overlooked.
My stack came into being so that I could do more with the B2 set I had so that they got more airtime. The set is both a stack and solo pieces.
They really are a fun little kite with massive wind range and I think a lot of people overlook them (which is why we don't have the numbers to justify a pro model).
Granted they're not as good for team as a 1.5 but for a solo pilot and/or if you already have a 1.5 set... They are fantastic.
I also think they stack great and have my set rigged in a stack. The mid has everything attached all the time and I pull off the std and vent as needed.
In solo form I use the same frame setup as you, in the stack I use 4-3-3 drom front to back.
The wind was ripping (way past xtra vent), the lines are short (check all the mistakes), the frame is (necessarily) stiff, the camera is head mounted (lots of shake) and the video editing package is weak, buggy and prone to corrupting your project.
But you know what they say about being handed lemons
Thanks for the encouragement, hopefully I can get a video with some decent flying out in the not too distant future.