Mik,
I have had a 45 gram cook setup (and even a stupid 26 gram cook setup) and I have owned the JB Sol Ti and the JB Sol Al.
The very basis of your original question is nearly impossible for anybody to really do anything other then share their own thoughts on what they prefer.
Can the weight of a JB be justified? Of course it can. If you are a hiker that usually has a 14 ounce pot setup, then an 8 oz pot setup can be justifiable.
Then again, is 100 bucks worth 6 ounces? For you, maybe. For the next guy, perhaps not.
So many other here have said it so well in their own ways. The simple fact is, you totally failed to give us any parameters to work with in order to truly provide a solid answer to your question. Things such as how many miles do you hike a year (and that sub divides into required questions/answers such as: are you a weekend hiker; are you a long distance hiker; if the latter, what trails do you typically hike on; and therein, how many days between resupplies, and the list could go on and one) . What is your existing setup. What temperatures do you typically hike in. Are you faced with laws that prohibit open flame cooking systems (such as SoCal PCT hikers have to deal with). And a whole lot of other variables that you did not give any indication to, which would help us answer your question.
With that, all you are doing is throwing a blank question out there… and thus, going to get very little more than a bunch of answers (myself include) that really do nothing to answer the question.
As have been posted (a lot) here at BPL over the last few years, there are some very solid numbers that have been presented to show that the JB Sol Al can be an extremely justifiable cooking setup, within some very specific situations, on some very specific trails, and under specific circumstances. Heck, the same could be said of “the beast”, the MSR Reactor. I have seen a few documentations where the MSR Reactor is the best performing, best bang for the bucks, and best ounces to performance stove that there is – under a set of specific situations.
Nobody here can say that the JB is the best overall stove in the world. Nor any MSR stove, nor any can stove, nor any tea stove. We each have to find what our style of hiking is, and from there take the stove that best suites our style of hiking.