92dxman wrote:
Are Kobo's the easiest to use in general and most friendly to multiple file types?
Kobo exists in the weird niche much like Roku where is too small to directly compete against Amazon and Barnes and Nobel so it supports most of their formats but would like to do it's own thing too so it has it's own store. I don't have first hand experience with their ereaders but I'm leaning heavily in that direction to replace my aging Nook Tablet as their new models appear to be pretty well reviewed, their store has gained some traction, and Calibre has drivers for their devices.
Supported formats for the Kobo Aura ONE: EPUB, EPUB3, PDF, MOBI, JPEG, GIF, PNG, BMP, TIFF, TXT, HTML, RTF, CBZ, CBR
Supported formats for the Kindle Oasis: .azw, .bmp, .doc, .docx, .gif, .html, .jpeg, .mobi, .pdf, .png, .prc, and .txt
Supported formats for the Nook Glowlight Plus: ePub, PDF, JPG, GIF, PNG, BMP
The major item of note here, and I made a mistake on my previous post based on some older information, is that Kobo does not read .azw formats which are Amazons DRM protected files. So what you need to consider is where you're going to buy your books from or how you're going to get them onto different devices.
Minor DRM Rant
Stores like Baen's (I read a lot of Sci-fi) sell the books without DRM in .epub format which allows you to put the book on an device you choose and read it. Others like Amazon and Barnes and Noble place them in a container which must be decrypted in order to read them.
Unfortunately that can lead to some problems since Barnes and Noble locks the DRM to whatever credit card you bought it with so if you have replaced the credit card (I've had 5 different numbers in the last year, Thanks BoFA!) You may have to reenter that old number to unlock the book you purchased several years ago and want to read it again. Since that may or may not be possible you could end up buying the book again.
For that reason I strip all the DRM using the previously mentioned Calibre method if I buy from Amazon or Barnes and Noble. I generally try to stay away from their stores because of that nonsense so there is an immense bias on my part against them. If you want to use Amazon's store you'll have to convert the files to epub and side load them. Calibre makes this pretty easy.
Don't even get me started on how I feel about berkeleying Topaz files.
end rant
I'm sorry this was a technical answer to an easy question. Annoyingly the market is heavily fragmented due to publishers and device manufacturers insisting on different DRM standards in an attempt to control where the market goes.
If you are ok with only using one source for books an Amazon Kindle is a pretty solid choice.
If you want to shop around a bit for either DRM free files using a multitude of other stores out there, or deal with a bit of a hassle with Calibre, and buy from where ever is having the best sale on the book Kobo is the way to go.