What works best for you, thin or thick string at high or low tension? A description of your style and smashing power will help clarify things.
I use BG-85, which is 0.67 mm I believe and I strung it at 24lbs. On an adrenaline rushing day , I can smash thru the badminton net and even smash thru a couple racquet string beds one night. In my experience, I have better "power" when using thinner strings at higher tension.
Thin strings for life!!....or only when I can afford it. I usually use BG66 or BG85 strung at 23lbs since I'm afraid my racquet would break. But recently I'm low on cash, and tired of gettting strings snapped every month or so. So for the mean time, I will am using BG70Pro (which I bought 2 years ago) and the freaking string is to durable for me!! Also, I feel that thick strings kill the feeling and create a dull feel compared to Bg66 and BG85, which gives crisp sound and feeling.
Check the market, u will see the fact is, most of the "high end" strings are thin ones, which are 0.70mm - (i.e. BG85, BG68Ti, BG66, etc). Most of the crappy strings which are below $1.50 USD are usually 0.80mm+. Therefore, I guess thin strings do provide better power as well as control.
Even BG65, which is widely accepted by various pros, is only .70mm, I think. Most of my rackets are strugn with BG65, which give me decent power. However, I am still far far far away from being a pro.
judging from the discussion before, BG-65 has probably the best performance/endurance ratio out of all the strings, which might be why most pros use it.
Add "price" to ur ratio, too. Pros won't care, since they get them for free. But I think many of us do care.
Absolute power would be the BG-66 0.66mm thick but it will make a hole appear in your raquet since it isn't durable at all.