To give a perspective on what
@Escape Hatch is asking about, the E-rated tires do have a thicker more durable sidewall to handle heavier loads, while it might be slightly stiffer if you run them at normal air pressures that you currently run your tires at it is hard to even notice the difference, if you throw 50psi of air in them without a heavy load then yes they are going to be harsh riding, and the first 1k or so miles they will probably feel a little stiffer than the factory tires, once the sidewalls have flexed some though you honestly can't tell the difference unless you put more air in them. The only downfall is the weight of the tire, you will lose some mpg and performance due to the weight, but you will also gain a more sturdy tire that can be abused more. To break the sidewalls in even quicker you can hit a forestry road and lower the air pressures to around 25 and run it for a few miles, this will help to break in the sidewalls to allow more flex and therefore not make it ride as rough initially. Personally I think the E-rated tires provide a better more comfortable ride after they get broken in.