このアイロンは重おもすぎて、使つかいにくいです。
This iron is too heavy and hard to use.
このアイロンは軽かるくて、使つかいやすいです。
This iron is light and easy to use.

Structure

新あたらしく買かった音楽おんがくプレーヤーは使つかい方かたのせつめいがわかりにくくて、こまりました。
I was having difficulty with the explanations for using the music player I just bought because it's hard to understand.
日本製にほんせいの電気製品でんきせいひんはこわれにくいので、長ながく使つかえます。
Electrical appliances made in Japan does not break down easily so you can use them for a long time.
このれいぞうこは中なかが広ひろいので、そうじしやすくて、気きにいっています。
I like this refrigerator because the insides are spacious so it's easy to clean.
(電気屋でんきやで) (At an electrical appliance store)
A) この音楽おんがくプレーヤー、どう思おもいますか。
B) いいと思おもいます。機能きのうがかんたんで、使つかいやすそうですね。
A) What do you think of this music player?
B) I think it's good. The features are simple and it looks easy to use.

This is used for both positive and negative senses.
Since “～やすいです” and “～にくいです” are I-adjectives, they can be used together with “～そうです” to express supposition, etc.