The Komo Val Battleship was the largest Klingon warship of its time. These mammoth ships were commissioned into service prior to the testing of the Federation Excelsior Cruiser. For a short period of time, the Komo Val shifted the balance of power along the Klingon/Federation border in the Klingon's favor.
The raw economic cost of the Komo Val Battleship limited their production runs and curbed the desire to produce the Komo Vals in mass quantities. This fact would later come back to haunt the Klingon Empire, as the Federation successfully streamlined the production process of their own Excelsior Cruisers allowing them to be produced in great numbers. In one-on-one battles the Komo Val was superior to the Excelsior, but with Excelsior Cruisers outnumbering Komo Vals two or three to one rendered their combat effectiveness greatly diminished over their first years in service.
The Komo Val Battleship was kept in service, but it was eventually replaced by the Vor'Cha Attack Cruiser - a warship that could be built in large quantities for a reasonable cost. Very few Komo Val Battleships remain in service. Those that due are operated by house fleets.