I have had heavy horses for the last 20 years.
This is just my opinion based upon 20 years on the breeding/showing/working circut.
They are not for beginners! You can get away with a lot with smaller horses. Any accidents you have will be bigger. If they are not handled consistantly and firmly they go from 'Gentle Giant' to lethal machine in a flash. With a light horse you stand a chance. A heavy will throw all of its weight about.
Everything costs more! It is like keeping 2 light horses!
Check that your farrier is willing/capable of shoeing one. I pay 120 pounds for a set. Heavy horse feet grow quicker and they wear their shoes out faster. When in work 1 set lasts 4 weeks.
Double the costs for wormers and suplements etc.
My Clydes each munch through a bale a night.
A heavy horse is lucky to reach 20 years old. They are not noted for their long life spans or soundness. Its the wear and tear on the joints that gets them in the end.
Couple this with the fact that they mature very slowly (still growing at 6/7)and they don't have a long working life.
They most certainly are not plods. Clydesdales have better movement than shires. They are not designed to be ridden and are totaly the wrong shape. They were designed to pull, not carry weight. As a ridden horse, they are not weight carriers.
Under saddle they are wonderful armchair rides. However, you are looking at years of work. They can't be worked hard when young because of their joints and uncoordination. I back mine at about 5-6 years after a couple of years of driving.
Then they start hacking and flatwork. Because they are not designed to be ridden they find everything much harder. You need a large school! It has taken 5 years of schooling to get my ridden clyde in to something aproaching an outline!
As for jumping, people do. I do on occasion, but I dont make a habbit of it. Its the weight thing again. 1 tonne crashing down on to joints that were never designed for such stress
They come with their own interesting selection of problems.
EPSM (It is estimated that half of all heavies have it or will have it at some point)
Grease/Grapes/Pastern dermititis
I find there is a lot of sexism around heavies along the lines that they are 'not for lasses' so if you are a girl this might bother you. I get my husband and his friends to show mine. Sadly the sex of the person on the end of the lead rope DOES matter
I would say that they are for enthusiasts. If you get a heavy, enlist the help of an 'old boy' (or girl!) to keep you right!