I have a 27" seven tuned normally. The tension is not that big of a deal with it versus a 25.5" fender. As far as adding another string, I found it a heck of a lot harder to get the hang of than a fifth string on a bass. Chords are different, your playing with a pick generally nails the lower strings, and that B is now there so it is hard to miss it when trying to sound like a regular tuning. Odd things. But after a while, you get used to it and it becomes normal. The longer scale was not hard to get used to, other than my hand will fatigue faster from the stretching. Make it feel like you are a master when going back to a regular scale. Only for a moment...
Patrick