ETA; sorry if this is scattered! I have had sporadic internet access so I wrote this over two days.
I'm going to back you Linds - I would say a working bred or "old style" Aussie would be very similar to an ES!
I always preface these kinds of posts by saying I am a novice to this breed with limited first hand experience with English Shepherds. I have Quinn obviously, I've met an aunt, her dam, and her granddam, I am friends with and herd with the owner of another ES, and I have a dog that is actually related to Quinn (they share the same grandsire) come into work occasionally but that's about it! The English Shepherd community is a very close and active one though, so thanks to the internet I get to stay in touch with and hear about lots of other dogs.
Briefly back to the Aussie thing - I had Aussies as a kid. My childhood dog that we got when I was three was a working bred bitch, then my dad got another Aussie bitch when I was 5 who I assume was probably more pet-bred. We also fostered others although they didn't have as strong an impact on me. Our working bred, Jasmine, was a fantastic dog! Extremely stable temperament, great with kids, great with the horses, active but had a great off switch, very smart, biddable and forgiving. I would take another of her in a second! I was however turned off Aussies when I was looking to add a puppy (that ended up being Quinn) because the ones I'd been seeing lacked the stable temperament and strong nerve that Jasmine had. I live in Ontario, so the majority I'd been seeing were likely show and pet bred, but it did leave me hesitant about getting back into the breed. If I lived in Alberta I'd probably have a better time trying to find working Aussie breeders!
I went with the English Shepherd because the standard and description of the breed reminded me so much of my childhood Aussies. They should absolutely be your all around farm dog - able to work a variety of stock in all kinds of conditions, hunt vermin, guard, and be a good house pet at the end of the day. I think a good Aussie and a good ES would be a very similar dogs! Quinn is a little less sharp or sensitive than a lot of Aussies I've met - she is not noise or movement reactive and not many things seem to weird her out or spook her. This also varies but I think, generally, ESs aren't as barky. Compared to a BC, they don't have that intensity that seems pretty unique to the breed. I would also say they're less prone to movement reactivity and obsessive behaviours that can sometimes be a problem with BCs (and ACDs for that matter - Dally can be OCDish). They tend to take themselves pretty seriously (and expect the same of others) - they are thinking dogs, not reactive. They probably have more hunting and guarding instinct than a BC, which can be a pro or a con depending on your preferences, and may be a little more tolerant than some sharper BCs. Quinn has had so many little kids run up to her and grab a hold of her in a split second and she is always very accepting and happy to see them! As far as working ability, English Shepherds are loose eyed upright herders like Aussies. Many dogs will bark, many will grip, although it does vary from dog to dog! Quinn does neither, for example. She is a very drivey, quick moving dog (and I know others like her) so as of yet she hasn't had to put any more pressure on stock. I could see her gripping if they weren't respecting her but it's not her first instinct. They don't have much eye because they are meant to work in close contact with stock if needed without stressing or scattering the herd. English Shepherds are less ... I can't think of the right word, perhaps biddable? than BCs. They can be particular in the way that relationship with the handler and working is closely linked. They are the type of dogs that like to work with you. They generally don't do well with lots of drills or repetition and will often question their handler if they don't understand the purpose of the task. They seem to learn best through doing actual "real life" tasks with their handler. This is that independent nature showing through!
Linds is right in that there is a large variety of the breed. Quinn and her relatives are quite alike in the way that they are pretty moderately sized (40-50 pounds) and high drive. Quinn and her mom especially are quite high energy, busy dogs that have been referred to as multiple people a little BC-ish. Quinn is a fairly intense dog when turned on - she gets very quiet and serious about her job and does it fast! Quinn does have a great off switch though, and apparently has more of one than her mom. Quinn is also a little more social with people than the relatives I've met - they were pleasant and happily accepted pats but not overly excited to see me and didn't give me much of a greeting. Quinn is a little more exuberant with some people - others she gives a very quick greeting to and moves on. Her cousin who comes into my work is very friendly and was in my lap within 10 minutes, but his attention was always on his young owner. They are all stable dogs with good nerve - Quinn doesn't get shook up very easily and can take some correction. The English Shepherd we herd with, who is a good comparison to Quinn as they are the same age and live in the same kind of environment (small farm), is a much softer dog. She is more laid back and easy going, but she's not a dog that can take much correction before turning off and she doesn't recover immediately. She is still a very reliable, stable tempered dog though and is such a wonderful girl! She has this amazing calm aura to her and is just so innately good - her owner says she's her easy dog and that she hasn't even done that much deliberate training with her. She just knows what she wants and aims to please. English Shepherds seeming to innately know what they need to do and figuring out the daily routine and taking it into their own hands is a common thing - the fact that they can be independent workers and that they bond very closely and aim to please their owners is a good combination!