In reply to Bjartur i Sumarhus:
Have had a 5M bell tent for a couple of years, but have only used it for weeks at a time. The 5m is a bit like a big top and is a popular place for playing/ sleepovers.
They are very quick to pitch so putting them up and down (in the dry) is easy. long term pitching will fade the canvas a bit (thats's a good look) and leave a patch of dead grass behind.
There are "glamping sites" that rent out bell tents that are pitched for the whole season that don't seem to have any trouble. Re-proofing helps to shed water and dry quicker but i haven't got round to doing mine yet, you shouldn't get mildew unless you store it wet.
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