[Galaxy Note 10.1 (2014 Edition) Q&A, Help & Troubl] BarryH_GEG:
All the faux-Office apps have limitations.

Some they share...

If you're adding or changing formatting to an existing document or adding content to a document originated on a PC the formatting can change and you can't see it until you open the document in the corresponding "real" MS Office app. So what looks fine in the Android app can look different when a recipient on a PC views it. Documents created and modified exclusively within the Android app tend to fair better formatting wise.

Spell checking sucks in Android. Some of the apps below offer spell checking and some don't. Keep in mind if you're using a BT keyboard word suggestion is disabled so there's no "real time" spelling support. That doesn't just apply to faux-Office apps it applies to pretty much all of them.

Only Polaris and OfficeSuite Pro natively support multiview which is something to consider if you do a lot of content sharing between apps when creating documents and projects.

Before commenting on the faux-Office apps here's an app I use when I want spell checking and either am using the BT keyboard or when the app I'm using doesn't offer it natively. It's called Spell Checker Pro. It's essentially an HTML text editor that allows you to create lightly formatted text, spell check it, and then send it to apps (MMS, e-mail, S Note) and copy<>paste it in to all others. The fact you need to create content in one place to ensure it's spelled correctly and then figure out how to get it to another place for actual use speaks volumes of Android's limitations as a productivity platform.

https://play.google.com/store/apps/details?id=com.flipdog.spellchecker.paid

Quickoffice

Bought by Google in November, 2012. It's a nice clean app and offers spell checking. Formatting's fairly easy to apply but it's not as thorough (as many options) as some of the other apps. It's free which is a plus and Google's been working on improving it since they bought it. The major downside is cloud integration - it only works with Google Drive.

OfficeSuite Pro 7

I like this one but it's a PIA in a couple of ways. First, it uses its own clipboard so you can't copy<>paste with the Samsung clipboard which means you have to copy<>paste directly from app-to-app. If you have a lot of stuff you've got in Scrapbook or accumulated in the Samsung clipboard that you want to use in a document you're creating you're kind of screwed. It offers an optional spell checker and an add-on dictionary that vary in price. Their speller's pretty meh and sometimes makes bizarre suggestions. The dictionary integration's nice when you're looking for definitions, antonyms, and synonyms. They're kind of kluged in their implementation though. A misspelled word in a document shows up with a red underline. Rather than allowing you to spell check it, it allows you to look it up in the dictionary and then manually make the correction. If you want to spell check that's launched via an icon in a formatting bar at the bottom of the app. You can get it anywhere from "free" (Amazon App Store) to $14.99. The add-ons are $4.99. It's a very effective app with great formatting and editing options but it's not without its idiosyncrasies.

https://play.google.com/store/apps/details?id=com.mobisystems.editor.office_registered&hl=en

DocumentsToGo

This is a pretty decent and thorough app. It offers no spelling support other than what's provided by predictive text and autocorrect on the keyboard - which are both disabled if you're using a BT keyboard. So its got great formatting support but the lack of spell check is a real issue.

https://play.google.com/store/apps/details?id=com.dataviz.docstogoapp&hl=en

Polaris 5

Polaris is a decent app. It offers no spelling support and the formatting, while decent, is fussy to use with lots of cascading menus and spinning wheels to select what you want. It has great S Pen support because of its integration by Samsung.

Microsoft RDP

This has become my "go-to" method for managing Office documents. It allows you to RDP in to your home or office PC and use real versions of real Windows products. It works well with a BT keyboard and mouse and, because it is "real" office, allows you the comfort and flexibility to do anything you'd normally do on a PC. It's free which certainly can't be argued with. The downside is the PC you're connecting to has to be on all the time and if you're traveling and there's a power failure or the PC unexpectedly shuts down your pretty much screwed. You also have to be on a Pro or higher version of Windows to use RDP. You also obviously need to connected to the Internet. I have a 3G N10.1-14 with unlimited data so that's not an issue for me. At times I'll work up a document using one of the local faux-Office apps I have installed and then open it via RDP just to do the final editing and formatting.

https://play.google.com/store/apps/details?id=com.microsoft.rdc.android

The bottom line is we all use productivity apps in different ways and to do different things. There's no cut-and-tried universal "winner."