I also prefer exporting from the EBSCOhost platform than from ProQuest. PQ has made it very difficult to export large numbers of records...they want your institution to purchase their Text and Data Mining product for this.*
Meanwhile, exporting a large number of records from EBSCOhost is a snap (except that they took away the ability to add a subject line to the email that delivers your download link).
Jane @ Purdue
*If for some reason you want to export every field in a ProQuest record, you can ONLY do it with a .txt export <grumblegrumble> Fortunately this is not so relevant to exporting records for a systematic review, because we usually just want citations & abstracts.