Felt like about 1500m climbing to me, certainly one of the easlier bike courses. Roth is my Ironman PB course and I did it 2 weeks after Ironman Germany.
Roth is well known as a PB course Jan Frodeno broke the Iron Distance course PB there this year setting a 4.21 bike in the process.
Roth bike course if faster than a flat course, there are no climbs to be worried about, Solarerberg is about a 1 mile drag with about 10,000 people on the hill cheering you along (a few less on the 2nd lap)
Ive walked/shuffled many Ironman runs, mostly a result of being unable to consistantly run train due to various recurring injuries.
Those involving mostly walk have taken me a around 7 hours. But thats without specific training to walk the 26.2 miles. I think if you trained for it and adapted a strong power walk, sub 6 hours should be achieveable purely by walking.
As said all depends on your swim bike but an average athlete should have around 8 hours to cover the 26.2 miles?
Re IM it appears to me that there's cheating going on for some of age group qualification. Clearly not everyone is doing it and I'm not casting aspersions towards individuals but I've seen to many working packs at the front end of races for it to be a coincidence.
I was watching the full Kona coverage last weekend, as the male pros are on the leaving Waikoloa you can see groups of 50-60 riders going the other way, then big gaps, it's groups together not riders spaced out at 12m. its fair for draft busters to turn a bling eye in the first 10-20 miles but this was 40-45 miles in.
Agree it's probably $$$ that's probably the factor with WTC.