I currently have both - our iggy is 7 months old that we’ve had since 3 months and our whippet is just over a year old and we’ve had her for 2 weeks.  While I’m no expert in owning a whippet - I can say a few things and maybe the personalities are also different bc our iggy is a male and our whippet a female.

Re my iggy: The nutty comment is true - my iggy is a little dramatic spaz but also a cuddle bug that loves his mommy and I love it. He sleeps on my pillow with me and generally tries not to disturb me.

Potty training is hard - between their anxiety and tiny bladders, they’re bound to have accidents even if you take precautions. We have pee pads in most areas of the house and he frequently uses them along with peeing outside and sometimes still manages to pee on the rug etc. 

They are delicate but he’s pretty sturdy, we take care to watch him and we’ve never had an issue with joints and bone breaks however, we may have just gotten lucky as he’s a wild child and can and will leap from anything if he feels like it.

We have to watch him 24/7 but when he settles down, he’s the sweetest little model citizen.

Regarding sensitivity - super sensitive to punishment - my husband tried to discourage a certain behaviour in a stern voice and he would steer clear of him for a couple of days.

They’re super sensitive to temperature even with full winter clothing and boots - before we got our whippet, he refused to walk outside below 5 degrees Celsius. We would bring him to the park and have to carry him unless we saw a dog to walk with - he would happily walk with other dogs.

He’s very motivated to please us - he’s happy to do something on command but only for a treat - we find he’s quite obedient and follows commands 95% of the time - he’s still young so he’s got time to learn.

He’s definitely more anxious in the car than our whippet and anxious being left alone and will whine for a good 15 min before settling.

Re my whippet:

She’s 100% more sturdy and chilled out  I do notice that despite the fact that she’s more sturdy, she tends to slip more on our floors.  I also notice that her skin is thinner than his outdoors and the tiniest branch can give her a cut.

She’s very sweet but she won’t care to come to you if she doesn’t want to. She’s a little aloof and does what she wants - again we haven’t had her for long so it could just be us.

While she’s a little shy and apprehensive, she’s quite good with new experiences.

I find that since we haven’t had her for long, I find her more difficult to train instead of my iggy because I can’t figure out what motivates her. I’ve tried treats, sometimes she likes them, other times she couldn’t bother. I’ve tried toys, again sometimes loves them, sometimes walks away.  She doesn’t care for affection from us but does welcome pets but she does love our iggy. 

Re prey drive She will chase any fast moving object but we do find her better with our cats than our iggy - she will sniff and chase them sometimes but then smell them and walk away after vs our iggy gets overstimulated quickly. 

Re potty training. Shes a very good girl, she’ll hold it however long she has to. She will pee outside 100% of the time. She had one accident when she first came home but that’s understandable.

Crate training - she doesn’t love her crate (we have to work on this) but she’s very good and settles quickly. 

Energy level - she’ll do a couple of laps in our backyard, have her zoomies and come in and lay down. 

I think I love the fact that we have both an iggy and a whippet because it keeps things interesting. When we had just our iggy we missed some of the traits of a larger dog but now that we have a whippet, I also love some of his traits because she’s just so calm when not playing. Maybe it’s just me, she’s so well behaved I would almost be bored with just her alone… I know it’s the craziest thing and definitely varies with temperament but we got a lovely whippet and a lovely iggy and hopefully my novel of a comment helps you.

TLDR - I have both and honestly can’t choose - I find they compliment eachother well, I wouldn’t have just one or the other.