When buying a rucksack or backpack, I really don’t think that the brand name matters, although one which has a recognised name is likely to be favourable at first glance as the logo or name will be a trusted one so it could be tempting to just pick up one with a brand name that you have heard of. This is the same with any product, it is human nature to pick out the item that you have seen brand advertising for as you are lead to believe that it is somehow better than any other brand.
Just because a backpack or rucksack is not made out of a brand that may be familiar they should not be instantly dismissed. By taking a more close inspection, you may find that they are made out of the same material and could have the same kind of compartments or straps for example that the well know brand bag offers.
As long as the bag is durable, waterproof and is made from a material that will be able to breath in hot weather, it shouldn’t matter what brand name it is. Backpacks and rucksacks are not really fashion items, so by using a less known brand you will not really be affecting your credibility, as they are an item of practicality more than anything else.
Comfort is another factor which should be considered, as backpacks and rucksacks can be worn for many hours at a time, so they should be tried on for comfort to make sure that the straps are comfortable and the back sits nicely on your back. This should mean trying out all the bags that suit your needs and are in your price range.
Unless you are very familiar with hiking or camping equipment anyway, it could be that a name that you think is unknown could turn out to be one of the top brands. It is all down to personal choice, but choose a backpack or rucksack based on the size you want with the features you need, and stick to your budget. A less known brand could still offer you the same features as a well known brand, but could cost you less money, leaving you more to spend on your trip.