The Orion V has three tons less armor than the K model, making room for an additional SRM-4 rack on the right arm. This increases the Orion's power, but many pilots consider the loss of armor to be risky.
Although it nominally has less armor, the fact that you have 42.5 tons to play with and a generous amount of hardpoints, the ON1-V can be the proud bearer of the AC/20 paired with a considerable amount of light SRM racks for extreme stopping power.
Alternatively, you can use it as an LRM boat, mounting triple 15-Racks. With maximized armor, it may run a bit hot, but its knockdown power is hard to equal.
The Orion-V can be configured to be a brawler if needed. Instead of LRM's, 3 x SRM6 w/ 2+ tons of ammunition would be the weapons of choice. The remaining tonnage can then be spent on more armor, heatsinks, jump jets, and additional weapons.
The Orion V trades some of the armor the K model is known for to mount additional weaponry. This increases its overall damage output, but many pilots consider the loss of armor to be risky.