They have two things going for them.
- You can hop into an otherwise expensive mech immediately
- You don't have to pay to fix it afterwards.
- You don't get full cbills.
- You don't get any mech xp.
- You can't customize them.
- The stock configs are generally awful, largely due to inadequate heatsinks and ammo since weapons now fire faster than TT and armor values doubled.
But wait, won't this make people not want to buy their own mechs? Well, a few caveats.
- You still have to pay for any items/weapons/initial ammo you add into it (still free repair/rearm), and you can't sell or transfer equipment from the stock variant.
- Since the trial mechs are rotated, remove the "upgrades" option for them - no DHS/ES/FF/artemis. This is a necessity, since once one rotation gets phased out, since those upgrades are mech-specific, players would lose them. Plus, another reason people will want their own mechs (and then it might be ok for DHS to be an outright upgrade!)
- When the rotation changes, any items/weapons you bought go back into your inventory, stuff you can sell back later, put on a different trial mech, or put on your personal mech when you can afford it
- You still don't get to choose which variants are available, maintaining the incentive to have your own stable of mechs. Similarly you don't get full cbills or mech xp.
In fact, I suspect people would be more willing to spend real cash if they knew what kind of enjoyment having their own mechs could be, rather than accepting on faith that it has to be better than the frustration of the current trial grind. Test drives for cars only help if they give people a taste of how nice owning the car can be, not how awful a car can be until you buy it and change everything that sucked.