You won't get a good bike with dual suspension for 300$ unless you buy something that's 10 years old.
What you'd get is shitty components that are annoying to work on, need work frequently to keep working, poor quality tubing that's quite heavy, poor welds and poor build overall (think failure, not ugly) frames that are typically misaligned so nothing quite fits together, altho the only really critical part would be bb threading & play in the "suspension", but since they fail on both the bikes occasionally ghost shift. Full suspension that is absolutely useless, seems to be a gimmick that serves the purpose of looking like the real thing, adding mass and hurting aero in the process.
At their price point, if they didn't put gimicky shit on them like suspension, disk brakes, riser bars, gel seat, etc. then they could be of good service as form of transportation, but because they have to make way too many compromises to keep price low you end up with a bike that got put together in <15mins by a worker that's likely unskilled. So you get something that's definitively not safe out of the store, it'll get put together wrong and won't be adjusted even close to correct, so you'll have to pay a bike shop to go over it completely for you or diy, but even then you'd still have a barely ridable pos.
A better question would be: What isn't wrong with these bikes?
My suggestion would be to go check out bikes in local pawn shops, maybe take pics and post here.
Check out the disclaimer here, it's cute:
http://www.huckjambikes.com/
This video rocks also (bike is a Pacific):
http://ca.youtube.com/watch?v=I9w3Gbur74o
Disclaimer: the main bike I'm currently riding around is a box store POS, it has no suspension and the only original parts left on it are the steel BB & headset, the bb is clearly on it's last legs - just hoping it will not biodegrade before the end of winter.
