I know the the QD detailer thread has been done to death, but i have a question regarding good QDs over Z-2 Pro. I love how Z-6 maintains the gloss, but i find myself going through a bottle really fast. I would like to buy a more economical brand in perhaps gallon sizes that compares to Z-6. I'm looking for a QD that enhances gloss like z-6 and not too much concerned about adding more durability cuz z-2 does a great job with that already. I've been thinking about Poorboys or Chemical guys QDs that enhances sealants. Any recommendations? Thanks.