NO OTHER foreign manufacturer will give that much BANG for your BUCKS as KTM currently is ’. drop dead gorgeous and most powerful in its segment!
As far as seating posture is concerned, every sportsbike has a lean-forward stance ( until and unless its a sports cum tourer like CBR 250R) & every time you brake, it puts more pressure on your palms and shoulder. so a continuous highway ride any longer than 30kms on a sportsbike will prove to be butt-cracking( things get worse in city ride) .
For your slipper clutch doubt, probably you read the track review of RC 390 on a foreign website/magazine. although , in traffic jams and B2B traffic any bike’s engine will throw inordinate heat due to the excessive use of the clutch. if you are not going for a drag race in between your 30kms commute( everyday) nor doing needless gear shiftings everytime in stop and go traffic, you will Never encounter any heating issue with the clutch.