Well, Microsoft has finally done it. With Version 5.5 for IBM compatibles, they've made Word as frustrating and hard to use as WordPerfect. We've done all the testing we want to, thank you.

What Microsoft did was to cross Word with Word for Windows. Unless you're new to the program or thrive on frustration, you'll gnash your teeth, too.Instead of Word's old bottom-of-the-screen menu, there's a 3Ps look: pop-up pull-down menus with point-and-shoot dialogue boxes. In dialogue boxes, everything takes longer unless you're a mouseophile.

To get to commands, you must learn to use the ALT key instead of ESC. The CTRL key now works wherever ALT used to. Anything deleted vanishes permanently (instead of being saved as scrap) unless you immediately Undo. Very few Function key commands stay the same (although, thankfully, you're allowed to reset them to mimic old 5.0).

You must learn new words for commands. Happily, they're words many newer programs use. Transfer Load is now File Open. Instead of moving a block of words with Delete and Insert, you Cut and Paste. That means hitting new letter sequences, and some are hard to remember.

The spelling editor now lets you add words to the program's main dictionary. That's a big no-no in our book, especially since there's no way to delete an incorrectly spelled word once you add it.

The new thesaurus is not half as complete or sharp as the old Microlytics' Word Finder. There are now many fewer choices and the new thesaurus hides the screen that used to show our original word in context. Grrr!

We did find one excellent change. Somebody must have finally heard our complaints that no program highlights copy blocks as well as dead old Benchmark, our first word processing program. Because Word now does the same thing: To select a block, you just hit the key for the last letter in the block. It immediately highlights that far and no further. Typing a period gets you to the next period, a comma to the next comma, an s to the next s and so on. Hurrah!

New dialogue boxes help hyphenation and macros. You can see a word's correct hyphenation onscreen. And deleting old macros is easier because with each macro name, you can see the first 50 or so keystrokes it creates.

Still, until Microsoft gives us better reasons to give up our good thesaurus, we'll stick mostly with Version 5.0. We'll keep 5.5 around just to use for cleaning up boilerplate macro files.

WordPerfect's latest IBM version, 5.1, mostly plays catch-up. You can mouse to select menu commands, move the cursor and highlight text.

Onscreen help is now context-sensitive and easy to find. You can opt for pull-down menus instead of the usual start-with-a-clean-screen look that's enough to scare away beginners and would-be converts.

The hyphenator is finally smart enough to suggest the right word splits. Mailing label printing is now as easy as in Word. There's printer support for Apple LaserWriter and other Postscript printers.

WordPerfect's greatest appeal was always being first on the block with an unusual trick. This version adds a few more. It types scientific and mathematic equations, putting in symbols for square root, infinity and such. The new Word calculates percentage, WordPerfect averages.

A new spreadsheet feature looks like it was moved in directly from the company's DataPerfect. It takes up to 32 columns by 32,765 lines of tabular data and automatically puts in tabular lines. If your word processed documents include a lot of tables with interrelating numbers, you'll find this a big bonus.

WordPerfect's awkward Styles listing isn't any easier to use. The manual's as much of a dog as ever but a good index still saves it. Our advice to WordPerfect owners is, `Get the update.' To new-program shoppers, we still say, `Shop around.' For instance, look at Professional Write. It combines simplicity, speed, smooth operation, ease of use and affordability with all the word processing features most offices need.

Its version 2.2 was the first popular word processing program to add a grammar checker. (Watch Word and WordPerfect follow by 1992.) It has a name-and-address file that pastes names and addresses onto letters without any typing. Neat! It can use a variety of printer fonts, but it's not much of a desktop publisher. It prints to Hewlett-Packard laser printers, but not to Postscript printers like Apple LaserWriter. While it imports from Word and WordPerfect, the new feature needs debugging.

It can't do columns, tables or automatic footnoting. Its dumb hyphenator turns problem into pro-blem and lawyers into la-wyers. You can't see the hyphenation onscreen except in Print Preview, so there's no easy way to fix improper word splits.

Its thesaurus calls "center" and "midway" synonyms of "internal." No! The program is getting too big to run on a floppy-disk computer. It uses 3 Megs on a hard disk. But at $250 retail, it's all you need to write letters, speeches and modest reports.