G6
Does that make it hard for you as a collector? I'm pretty fickle, and decks that I love and use all the time are 'meh' sometimes. It's more of a mood thing than the deck itself.
It's not a big deal though, as Le Fanu says, decks take up so little space. I would say keep it for a couple of years, if not decades.
I don't know that I would define myself as a "collector". I use my decks every day. Some I do keep for collection purposes, but those are very few, like say, Fantasy Showcase Tarot. I think it's cool that it is from 1980 and likely one of the first collab decks. I don't have endless space and decks/kits do take up space. I'm actually running out of tarot space.
Back to the original question though, I do give decks "a chance" because it's not too often I get one that fits all of my criteria for a deck I love. At the same time, a deck that needs "a chance" or more to the point, further investigation will remain with me for shall we say a probationary period usually 2-6 months or so and then the deck will stay or move along. I don't like to keep decks just to keep them.
Other decks are an immediate NO usually because of bad design/materials and will be moved along asap. Some decks that have been with me longer were once keepers, but then my taste/interest changed and I decided they no longer fit with me.
Hope this helps, but probably not, LOL! It's a very individual/subjective decision.