(OT: Karnac is right, but they will never do it.)
The 152 is a good plane.
(a) The 152 holds a supertanker load of fuel, much much more than any 190. Inexperienced people simply fly it way too heavy, especially at first because they just don't know any better.
(b) Shooting cannons well (especially 30mm) is much more difficult to learn. Learning to shoot 20mm AND 30mm at the same time is even more tough because the trajectories are much different. If you try to shoot like you have 50 Caliber you will be dissapointed everytime.
IMHO what you get are people flying too heavy and can't shoot trying the plane a few times and then putting it on the shelf thinking they have given it a fair try.
Perkwise, it is plenty cheap - a couple of spit/la7/niki kills in something other than the big 5 and you just earned enough to buy one.