Hello I am going to buy new double bass from Strunal store - prices the best at the source - great deals. Problem is - I've beeen saving for months to get new instrument and don't want to regreat something afterwards. So - most models avaible right now are with polyurethane finish. I think spirit varnish would be better but I would have to wait about 2moths... Second thing is - which should I choose - flat or swelled back - what's the difference in sound? Or maybe there are other considerations about that? Does anybody had similar problems or I am the only one with such questions...?