Having both, I’d say a border. Lovely little dogs. They can be independent, hunt, and be feisty. Cockers vary in energy levels, but most workers have plenty. Mine is, frankly, an exhausting, exasperating MENACE. She’s out most of every day with me or DH, and has various jobs which should in theory tick the physical and mental exercise boxes. There is just no off switch (except for at night, when she’s opened every door between you, snuggled on your pillows and is offering serious resistance to anyone who feels that maybe a dog bed would be a better place for her). She bounces through the door before 5am, stands poised at the fence for “just one last field sweep” before we go home at night, “we my have missed something”… clingy, jealous, bad tempered, nervous, intermittently reactive, thieving, shedding, intelligent and just so so SO very needy. If I dare leave her at home for too long and she suspects I’ve been somewhere fun, she greets me with a full on head hug and growls & snarls in my ear for a minute - I’m definitely being told off. If she’s feeling something else is getting her fair share of attention, she will snatch it, (books, gardening tools - if the puppy has had too long being fussed she’ll dash off and fetch his toys or bed), stand in front of you and start deliberately shredding them… although there’s a certain fairness to her malevolent moments, and she’s adoring, and driven and focused and actually really very useful, she’s a full time occupation, and there isn’t anyone who knows her who will do more than “call in and walk her” if we needed to go out for the day. I’m not sure she’d cope with kennels, and although she’s OK with DH, I’d not really relax if anyone else tried to take charge of her. She’s probably at the extreme end of the spectrum, (we are home #5) but I’m counting down the years until I can relax in the evenings again!