Yes, flat wall panel heaters are a good solution, but only in specific circumstances. They’re a more affordable alternative to traditional heaters that can come in handy if you haven’t got plenty of available space left or if your room already feels a bit narrow and cramped. They can even be painted to match the color of your wall to blend in even more.
However, flat wall panel heaters are a less efficient and durable option, so they aren’t really intended for constant use. They’re a good alternative if you’re only planning on using them occasionally and for a few hours, for example in your guest bedroom.