I might be wrong, but I seriously doubt anyone is hot blowing now they can't blow directly into the diffuser, it wouldn't be worth carrying the extra weight of fuel around now that its affect has been neutralised somewhat. Also I'm not condoning hot blowing, or criticising the FIA's outlawing of it (although changing the regs several times mid season was farcical), just their current obsession with stamping out something which is allowing the teams to make use of a waste product, which is surely in keeping with the current economic and environmental climate?
In terms of entertainment I meant it doesn't affect wheel to wheel racing, not the pecking order of teams. If you're adjusting the regulations to advantage certain teams and disadvantage others it effectively becomes sports entertainment. In terms of Red Bull making best use of it last season, how do you know that? The overall diffuser blowing concept was utilised better by Red Bull as they'd designed their entire floor and diffuser around it, but only Mercedes were using hot-blowing so the engine mapping arguably closed the gap at the front.
With regards to DRS compromising the integrity of the sport, I mean in the cheap and gimicky way it's utilised. Unlike off-throttle blowing it does affect wheel to wheel racing and has ruined many a good battle. The only positive of it in my opinion is the tactical side it offers with teams being able to optimise if for qualifying or the race. But there has been talk of doing away with it in qualifying and scrapping the only positive I see with the system.