I’ve actually had them since May. Normally I would have written about them earlier, but it hasn’t been a normal year (emotionally, anyway). A lot of my excessive anxiety and depression centered around them.
The integration wasn’t really smooth. Zoe accepted Mac pretty quickly, but took an instant dislike to Gus, and proceeded to bully him for months. (The fact that she’s half his size didn’t particularly matter.) It wasn’t the funnest experience to go through.
But, things have improved.
Gus
Gus, 2 years old at adoption time, was a cat I inquired about when looking at those available from Pet Patrol (the same rescue organization we got Zoe from 13.5 years ago). But we were warned that he was a very anxious cat, and thought maybe it wouldn’t be the best choice.
Shy he may be, but Gus knew how to sell himself. We went into his room at the shelter to see another cat, but she had no interest in us whatsoever. Gus, however, did. He purred and encouraged us to pet him. Whenever we tried to move away, he pulled out a paw to try to get us to stay. It was terribly endearing.

Once at our house, he initially crowded himself into a cat tree cubby and came out so rarely we were worried. His progress was quite slow, aided not at all, of course, by having a cranky old cat run at him whenever he dared to explore new territory.
But, he did expand his world from the cat tree, to the rest of that room, to the room next door, to the whole upstairs–a long phase, that one–but finally on to the main floor, which is where he now spends most of his time. Only in the past few weeks has he been regularly visiting the family room downstairs, and only this week (8.5 months later) become comfortable enough to plunk himself down and snooze in front of the fireplace there.
From the first, though, he had a fondness for getting pet, and at some point–while still mostly living upstairs–he decided that I was great and became incredibly affectionate toward me, with full-body cuddles and loud purring. Jean took longer (Jean is not the feeder), but now Gus will walk up to him for pets also.

He’s the most gorgeous thing, but it seems he had to learn everything about how to be a pet. (Well, not everything. He’s always been great with the litter and a good eater.) How to play. (All the toys scared him at first.) That he is allowed on furniture. (Still working on that, really, but he much more regularly goes on chairs now.) How to get a human’s attention (and that you might actually want a human to pay attention to you!). How to “stand your ground” against cranky old cats half your size.

We don’t know much about his background. He’d been running around a neighbourhood for some months, outside in winter, before the cat rescue people were able to trap him and bring him to the shelter. And he was there 4 months before we adopted him. I suspect his home before that wasn’t the best-est ever.
Gus has come far, but has more to go. I look forward to seeing the cat he becomes.
Mac
While pondering Gus at the cat shelter (while I was smitten, Jean was dubious), Mac–who had been sleeping–jumped up to greet us with a “Hey, how about me?” attitude.

Mac was a one-year-old sprite, mostly white with a few black patches. He’d been found stuck in a tree, and when rescued, the volunteer was able to carry him all the way to the shelter; he just stayed calmly in her arms. Mac was a Gus opposite, not only in colour but temperament: bold, unafraid, friendly, adventurous, chatty.
A one-year-old cat is still quite active, making him not really the ideal match for a 15-year-old cat. But as a compromise (?), we ended up with him, too. Despite Gus and Mac’s opposite personalities, they’ve always gotten along with each other. (They were in different rooms at the cat shelter, and only met at our house.)

Naturally, Mac adapted quickly. As already noted, Zoe accepted more quickly and easily than we’d expected–I think she found him kind of entertaining at first. While we were distracted for months trying to get Zoe and Gus to tolerate one another (as they do now), we probably didn’t give Mac quite enough attention. We’re trying to make up for it. (Particularly as Mac will pester Zoe when he’s bored, which she does not find in the least entertaining!)

Because given his age and temperament, Mac flourishes with a lot of attention. He taught us to play fetch with him (only the second cat I’ve ever had who will bring a ball back). When errant chipmunks came in the house, he proved himself a great hunter. Since winter, he’s had to make do with “hunting” Da Bird wand toys and some nifty animated toys like Hexabugs. I’ve also been training him to get used to going in the carrier, traveling in the car, and being on a leash. He’s proven a quick study on all counts, so he should be able to get outside in the nicer weather in a controlled fashion. (I don’t want him running off, getting stuck up another tree, and winding up somebody else’s pet.)

(Yes, he is micro-chipped. Still.)
He’s not as cuddly as you might think, but he is the easiest cat imaginable to pick up, he does sleep with us each night (very politely, down by our feet and not up on our heads), and he loves to rub his white fur all over our clothes, especially if they are dressy. And every once a while he will plunk himself down on your lap for a short sleep.

Mac has a fully formed character, but some maturing to do. He’s a very nice boy now; I expect he’ll become a lovely older cat. Maybe even develop some cuddles.