I've just tried using spear together with pure "vit" - defensive type and it seems quite difficult to use.
Spears have very low damage at low levels and there aren't as many spears available as sword/odachi. They also have lower stats compared to other weapons. I don't know about higher level though.
I did well against small number of enemy and but seems to be overwhelmed quickly by large number of them.
My biggest complaint about spear in general would be that spears in game have slashing as normal attack. Slashing leaves me largely vulnerable and shortens the distance between me and enemy. I would much rather use thrust as normal attack. Thrusting then back away immediately while keeping the safe distance is a basic strategy for spears and the fact that I have to use SP for that is kinda annoying. I don't know if that will change with higher level spears though.
So, can I use spear for solo runs? Is it only a support type weapon?
Please discuss about strategy for spears. I want to know more about them.