One thing I should perhaps mention about the plossl: It will not have a wide filed of view like the QX. Have a look at how things look through the QX in the outer 20-30% of the field of view. Do stars/planets remain sharp enough? If not then there is little point having that wide field that is made wide only with blurry views.
Check out this review on CN:
http://www.cloudynights.com/item.php?item_id=1162