Rory is the first male dog we've ever had, I grew up with lots of female dogs (springers & labs) and now also have Pippa and 2 labs (aged 10&11). When getting Rory my grandad (an ex gamekeeper whose owned countless gundogs) told me that male spaniels can be stubborn, but with my two I've found the complete opposite.
Pippa (female blue roan now aged 2 1/2) is very clever and picks things up quickly but is also quite stubborn and once she's decided she's had enough can be hard to motivate. She is very gentle and calm in the house but when out loves to run (at very high speed) and with her recall was the hardest thing to train and we are still working on this now.... She is the cuddliest and most loving dog we've ever had but is also the noisiest - she loves the sound of her own voice
Rory (1yr Black and Tan) has always been very keen to learn and rarely takes his name eyes off me when out and about. He is a complete softy and content to plod along alongside me when out.
Both toilet trained quickly, but both are not keen on being left alone however and this is something I think that will always have to be managed. Someone once commented that they are like magnets to me and if allowed to they would follow me wherever I go. If over attachment is something you are worried about could you perhaps look into a Labrador? I know each dog is different but we've always found labs are far more content when left alone and happy to chill out whereas the cockers have had to be taught to settle on their own. They also seem less attached to one person and will happily spend time with everyone (especially if food is involved
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I do agree as others have said its more about individuality than gender. Good luck with whatever you decide - I'm sure the right dog is out there for you and your family