Fishless cycling is easier, cleaner, safer and faster than cycling with fish - IF you do it right. If you do not follow instructions well; or do not have ammonia, nitrite, nitrate, pH and KH kits and are not willing to buy them, then you will run into exactly the sort of problems that others have had.
But then you can run into problems with cycling with fish - fish death, permanent gill damage from ammonia, suffocation from nitrites, stress-induced disease outbreaks for which the treatment will set back or destroy the nitrification bacteria, etc.
Fishless has no risk of permanent damage or death to fish, allows for immediate full stocking without repeated mini-cycles as is the normal case for fishy cycling, and teaches the hobbyist how to read and interpret test results.
Personal choice.