i used to be huge into bmx big into vert and flat land back in the day. then i got into mx. so i would rate my 2 wheel experience at about a 7/10.
However i have gotten way out of the pedal powered 2 wheel scene for far too long. I am searching through my local craigslist and i am seeing tons of really nice bikes in my price range $300-$500. 80% of those bikes are full suspension. is that an ideal bike for 80% of street riding?
My plans are to go downhill riding and trails with a couple friends. but about the other 80% of my riding will be getting back into shape and riding around the neighborhood with my daughter and nephew. does the rear suspension "absorb" any pedaling?
basically what im wanting is a perfect rock crawler and a baja all in one :D
i know there will be a compromise but is there a good chance of being happy in both directions?
what bikes should i avoid like death.
I'm very partial to trek bikes because i used to be sponsored waaaay back in the day by a local trek shop

I too was a long time ago mtn biker. I raced several races in a season and did ok. Won a "series" even.

I have just in the last 2 seasons really gotten into mtn biking again. I am finding myself looking for more of a "free ride" bike. I think you could phrase it as a "free ride/all mtn" bike. Be careful of the lower priced bikes. They can make them look nice but they are heavy pigs. Yes most of your riding will be on the street to get back in shape. If you go off into the woods and trails you will want something that performs. Yes, the rear suspension will absorb some of your pedalling energy. THe more money you spend on a bike the more your rear shock will be adjustable and sometimes even lockout if you don't need any suspension travel. A "cross country" frame geometry will be less comfortable but a faster bike. Since I am a rockcrawler I find myself wanting to climb over rocks etc with my bike. A "free ride" frame geometry is what works best for that. Check out your local shops. THey should let you demo some bikes. Even if you have to pay for the demo they will deduct that from the price if you purchase. Keep shopping in the used market. Hard to demo but if you research your frame geometry at least you can get yourself in the ball park.

Mtn biking is far less expensive that rockcrawling............but you can spend some money. Good luck with getting back and shape and congradulations.........you can be a kid again and go ride bikes.

I don't think you will find too much of a selection for a used F/S bike that will be a quality bike at $300.. At $500 your choices will be a little better. Go here www.mtbreview.com and search out certain models in the reviews and you will get a pretty good idea of what to expect. If you are not in a hurry, buy a nice, used frameset and buy the components off of Ebay or Craigslist and build a quality bike at the fraction of the cost of a store bought package.

id go hardtail for sure, i ride my dj bike everywhere even rode it from sf to la.

Definitely tough to cover all that in one bike at a low price. Since you come from a "stunting" bmx background I would recommend a hard tail but you are going to suffer with friends on the trails. A good front suspension will make a big difference in this case but you really notice not having rear suspension in this case.

Yes rear suspension will bob or absord peddle power on lower end bikes.

Actually just hit me if you look for a bike with a rear lock out you could have the best of both. I had a Cannondale Jekyll that I sold recently for $600 and it had rear and front lock out, this would actually fit your requirements very well.

If it is still available and is your size this would work well for you.
http://loz.craigslist.org/bik/2164648952.html

With what you described . I would suggest getting a 29" wheeled hard tail bike with 4" travel front fork . Gary Fisher , Trek , Specialized , Kona, just a few . good choices . I'm running a FSR 29er and love it ,I'm kinda ride all day in the mtns. guy . Most of the racing crowd are running 29er hard tails