I've had a similar problem when using the 'place' option, (from word docx) to import 400 pages of text (no graphics or other special features). The program becomes so slow as to make operating it successfully very frustrating. For example when resizing my text boxes to fit guidelines, it always (not often but always tends to freeze for some seconds. To give you more of an example, if I adjust any text box to meet guidelines, scrolling up or down simply won't occur for several seconds. Likewise if I wish to right click on a word to correct the spelling or when I wish to enter new text manually.
I should think its not related to my computer performance as I'm running this on a pretty decent i7 laptop.
Any suggestions on how this issue can be resolved would be highly appreciated.
Thanks
(Please note: the text involved is private and cannot be shared unfortunately)