Reinforcement vs. Materialization/Manipulation
So, here's the question: Which is better, reinforcement, or materialization/manipulation? If we look at people with specialization from Hunter x Hunter, it seems that these people are at an advantage to those with reinforcement. Yet, Kurapika wanted reinforcement because reinforcement users are balancedin offense/defense, and he felt that would make him fight better.
Thus, Kurapika had mentioned to his sensei that he wanted reinforcement and would not settle for materialization. However, in actual fighting, materialization had been to his advantage. If he hadn't been materialization, and had been reinforcement instead, he would have been killed by Ubogin's power, obviously because beginning reinforcement users could not achieve the power Ubo had achieved.
It also seems that materialization/manipulation users can have a larger variety of attacks than reinforcement users. For instance, I've noticed that most reinforcement users revolve around reinforcing the fist and punching others with it.
Of course, there are varieties, like Gon can switch between rock/scissors/paper, but Gon's strongest attack is still the one that is fully reinforcement, or the rock (which is basically a reinforced fist with kou). Another example is Phink's attack, where he swings his arm to determine the amount of nen to reinforce it with.
A materialization/manipulation user can materialize/manipulate anything, so they have a wider range of possibilities, (not necessarily abilities, since most people only develop one hatsu). Thus, materialization/manipulation users can create complex abilities that evade the predictable reinforcement abilities, causing them to have a better chance at winning.
Of course, much of this also depends on the hatsu you create, but your forte in which nen type often determines hatsu.
Also, true to Hisoka's definition, reinforcement users often are naive and tend to rely too much on their strength. They aren't as tricky as transformation users, and are too simple-minded in fights. On the other hand, materialization/manipulation users tend to be more logical with their fights, and consider the different possibilities of a fight. Basically, reinforcement users and materialization/manipulation users have different battle strategies.
Thus, perhaps reinforcement may not be the 'best' nen type, even if it is the most balanced. Every nen type has their own flaws and strengths (except maybe specialization) and reinforcement isn't always be great.