I wouldn't say that one is easier than the other. If you register an account on Imgur, you have access to all your updated images in one folder. You click on any of them, and the site allows you to change the size with one click. There are options such as small/big square and thumbnails of different sizes. After selecting a size, you just need to copy/paste the changed BBcode for it. But since Imgur no longer works on Bitcointalk, it doesn't matter any longer.
I was using it earlier but stopped it while ago and was using
postimages.org as it also give access to different kinds of BBcode according to your preferences.But yeah folder vise sorted images was good option if you have account over imgur.But now they don't give us access so we have really good alternative for it and forum dedicated without those proxy errors also.