I consider myself a pro mountain-ultra-trail runner. I'm not a pro road marathoner, but my next race is Boston and I have a side goal of running in the 2020 Olympic Trials (so don't say I duck competition). I like the most competitive races and seeing where I stack up against the top guys in the country and real pro road marathoners! Other ultra guys like Max King who have done 100-milers also "move down" to competitive road marathons (he is much quicker than me with a 2:14 PR and actually being top 20 at the Trials though). Not many ultra guys will "show their cards" and jump back down into a competitive road marathon or track event though. It is a hard transition to make.
When I graduated from college I had PRs of 14:29, 29:47 and wasn't All-American in NCAA DI xc (not even close). I had no illusions of ever going pro on the track because I knew I was too slow. If I focused on lowering my track PRs after college MAYBE (and this is a big maybe) I could have gotten down to lower 14-min for 5km and lower 29-min for 10km. But maybe not.
So I moved up in distance to the marathon. I focused on road half marathons and marathons for 3 years at Hansons. Got down to 1:04:32 and 2:16:52, which I would be happy to call my last time bests. I was mid-pack at the 2012 Olympic Trials (like 42nd-44th place or something) with a 2:18:30. I know exactly where I stand on the national scene. No illusions of trying to do "sub 2:12 and make an Olympic Team." I always thought MAYBE I had a 2:15 in me...but again that might be wishful thinking. I'm not going to focus on the roads that much ever again. It doesn't really matter (in terms of my career now) if I run 2:15 or 2:18, but I greatly respect and admire those that put in the time and effort (and have the talent) to run sub 2:16 (and sub 2:10 for that matter) because I kind of know what it takes.
However, I do consider my 16th place and 2:19:12 at Boston in 2015 (after moving down from ultras) to be a performance pretty close to "on par" with my 2:16:52 PB because of the headwind/weather conditions at Boston that day.
But I'm not a pro road marathoner anymore and I don't pretend to be. When I ran the US mountain running champs in 2012 for the first time (12km uphill at MT. WA) I discovered that I was a lot better at climbing than any flat road running. So I focused on mountain-trail-ultra running from then on and got sponsored to do that. I still like to try to go back to the Olympic Trials Marathon though, because I like to see where I stack up against the country's best. It is a very cool and unique experience and always a goal of mine over the years.
Unlike most people on here I have raced #AnySurfaceAnyDistance . The 100-milers (in the mountains and on trails) have not gone well for me. They are a lot different compared to other ultras like 50km and 50-milers. A lot depends on the type of trail you are running on (how technical), the weather conditions, and how steep the hills/mountains are though. I'll be back still trying at 100-milers soon enough.
Longer events are certainly not "harder" but there are more variables that can go expontentially wrong. Running in some of the most beautiful places in the world from New Zealand to the Alps is also a nice change from pounding the pavement (although I like both). Most ultras in the world happen to be trail ultras that explore some awesome single track. I have great respect for those that do well at 100-mile ultras (especially the "runnable ones") and those that run fast 5km/10km and even miles/1500m on the track. It doesn't matter how long the event is, the pain is a constant and if one tries and pushes themselves 100% then it is all hard. There is no event that is "the world's toughest" or "harder" then another when you are trying to optimize your own racing and training performances.
Oh yes, and my video yesterday about "Retiring" was an April Fool's joke. I love this sport of distance running and I will keep trying to do it as long as possible!
I like ultra runners fine and I'm not a very fast guy myself, but I can partially understand the disdain. Many people who do ultras do them precisely because they're too slow to be competitive at shorter distances. It's a way to get around needing speed. So all the speedy guys see them as slow guys trying to duck competition by moving to longer distances. I get it. But running high mileage can be a serious commitment and those guys deserve a lot of credit for how much they invest in the sport of running.