use the compound

Most people here would admit they couldn't shoot a bow as heavy as yours accurately at 20 yards.  Some people can, but from what I've heard most, certainly including myself, are MUCH better with lighter weight.  Also remember that if you do drop poundage you will need to adjust arrow spine as well.  
With the right bow and properly matched arrows, and 6 months additional practice, you might just suprise yourself on how confident you can become.  Even then, it will still be up to you to figure out tha maximum range you can cofidently hit what you are shooting at.  The distance will certainly be less than your compound.

If you are in the "I've got to kill one" mode stay with the wheel bow.I just started shooting trad last year.I limited my shots to 17yds.Had 4 bucks that close and did not shoot at any of them.The shot just didn't FEEL right.First year in 22yrs.that I didn't kill a deer with the bow.If you can limit your shots go with the trad bow.I would try a lighter bow.As for ethics that is between you and the man you face in the mirror.GOOD LUCK what ever you decide.You have a lot of time to practice before deer season.If you look at kills you will be amazed at how many are under 20yds.

My crotch hurts just thinking about stringing a 70# let alone shooting it too. I avoid shooting groups for hunting practice; and simply take a shot, retrieve the arrow, and repeat. Gosh it is great to have spell check on here aint it?

If your satisified with your form practicing the longer shots will not only make you more accurate at the longer ranges but if like me it will help a great deal with the shorter shots too.  Don't give up just keep plugging away and things will come around for you.  If you really like and want to hunt with the Barta it might be worth the $$ to buy a lighter pound bow to work on form issues and allow your brain to start correctly calculating the aim on the longer shots.  I was overbowed with my first bow and ended up with a lighter bow and my form is getting better and more consistant.  Good form will overcome a lot of issues.  And form isn't something you want to think about when there is a deer in range.  You'll have enough to worry about trying to keep your breathing and heart rate at managable levels...

It's not really a question of ability, but of restraint.

If you can hold out for 20 yards, you can hold out for 12.  If you can't, the wheels are a better option.

Molson hit the nail on the head.  I'm going to use that line.

How many of us read this forum and think that to themselves?  

And, I feel your pain, Bjorn!  I was thinking about my back, but you are right on the money.