Hi Bobson,
they'll probably be quite good quality, although you'd definitely need a tripod/mount as they'll be too heavy to hold steady for more than a few seconds at 30x.
Also, at 30x mag and only 80mm aperture, they won't have as wide a field of view as 20x for example, - and they also may produce quite a dim image on low to medium brightness targets.
I have a pair of 20x90's from AOE which are a delight to use - on a tripod mount
Just my 2c
