I had a somewhat similar progression through skis. I'm 5'3, and I started with a pair of 152 Dynastar Cham 87s. They're built for a very similar customer profile as the Myriads. Very beginner friendly, but it has a shape that does well off piste. Great for a beginner that's progressing quickly. I definitely thought I didn't like speed, but I did know I needed some additional stability on groomers.
I moved up to a Line Pandora 95, which was easily the softest and most maneuverable mid-90's ski on the market in a 162 after demoing and really struggled with my choice for a few weeks. The Dynastars really got me in the habit of keeping my turns tight and slow, and felt bad when I skied with good form, shoulders downhill, weight forward, etc. They were great on groomers, but they felt like a lot of ski elsewhere on the mountain. But after ~5 days, we started to get along and I figured out what kind of input they liked. I also figured out that I didn't mind speed. I minded instability and feeling out of control.
I've had a few friends make similar switches even without a big jump in length and shopping for your 2nd ski is easily the worst experience. All of your skiing and progression has been on 1 model that likes a certain style and forgives certain habits, and suddenly you get a new model you feel ready for and it takes you on an ego bruising. I definitely recommend giving them a few days and easing into it, starting on greens or easy blues and taking a stepwise progression into tougher terrain.
Now to talk about models, the Myriad is a really soft flex that's definitely beginner-approachable and lightweight friendly, so I can see how it has been a great companion. It is a wood core without any laminates that help stiffen up the ski, which makes it happiest at slow speeds. For your next ski, I'd go a little longer (that extra surface area will pay off dividends in powder) and something with a slightly stiffer build. Fiberglass laminates would be 1 step up. They're still fairly soft and approachable. Carbon laminates would be 2 steps up. They stiffen the ski without adding tons of weight, and tend to be more finesse and lightweight skier friendly. The Ripstick 94 fits in that class. The 3rd step up from there would be metal laminates, which really add weight and stiffness to a ski.
The Ripstick isn't the only option in that width class. I own the 102 W and I find it's extremely stiff and light, which doesn't provide the best suspension. I have skis that are light & soft that have the flexibility to absorb the bounciness in chopped up powder, and I have heavier, stiff skis that blast right through it. But I find that the newest construction of the Ripsticks get a bit of tip deflection and you feel it down the entire length of the ski. The ones that I think compete well against it are:
Armada Victa 93: This ski is discontinued, but has units on clearance. These are some of the easiest all-mountain skis on the market and they still use fiberglass laminates, but it will be a modest adjustment from the Myriads.
Volkl Blaze 94: Similar to the Victa 93. No carbon. But it does have a rearward mounting point that's typical for Volkl, so it rewards you for getting forward in a confident stance. An intermediate friend picked these up for touring after struggling with her Vantage 97 Cs (C's for carbon). She found these much more playful and approachable. She's also a tall & thin stringbean who has to think about how her weight influences the force she can put on a ski.
Line Pandora 94: They added carbon to the newest iteration of the Pandora, but it isn't as stiff and planky as the new Ripstick. The friend with the Blaze's found these a bit more demanding than the Blaze.
Blizzard Sheeva 9: These do have a partial metal laminate under the midsection of the ski, but they do a few other things construction wise to make it easy to ski. They made the tips quite soft to aid turn initiation, and they move the mount point more forward compared to peer skis, which also makes turns easier. The tails are soft & forgiving, and they're heavily rockered, which makes skiing feel surfier and makes it more nimble vs feeling locked into a turn. They're super nimble skis that are a blast in the trees and the bumps. And the metal underfoot really helps with stability and feeling grounded on groomers or when I'm at speed. I wish that the wider Sheeva 10 had been on the market when I bought my Pandora 95s, since I think they would've been an even better choice. Great quiver of 1 ski for a variety of snow conditions that really caters to a slower speed control freak that could match my style when I'm cautious, but really rewarded me when I skied more confidently. The "Blaze" friend also owns these as her inbound setup.
Maiden 91: Similar shape to the Sheeva 9 with the rockered tips & tails and nimble, surfy feel. But instead of metal underfoot, they use fiberglass laminates through the entire length of the ski. These are also made by a Colorado brand and should be easy to find as a demo.
Liberty Genesis 90: Similar to the Maiden & Sheeva with the rockered tails. These are bamboo, which is a really poppy, flexible wood that's easy to bend. They're stiffened with a mix of fiberglass, carbon, and 1 metal stringer (vs. heavier skis with a full sheet).
Older Black Pearls (pre 2020-2021 version): These laminates were fiberglass with a dash of carbon and used poplar, which is a light and flexible wood species. The new model is a hybrid wood core with some stiffer, denser species mixed in, and it adds a layer of titanal. It went from a 1300g ski to 1600g ski and meets a different customer profile. If the Ripsticks felt like a little much, the new BP88 matches it or is a little more demanding.
New longer Myriads, Pandora 84s, Mindbender 85s, or Maven 86s. If you want to keep your upgrade most conservative, these 4 skis have no laminates. Going longer will make them more stable (both between length and the fact that they make skis a touch stiffer for the larger people on larger skis). I think based on what you like to ski, the prior models offer you more room to grow without being wildly overwhelming.
From everything you like to ski, you definitely need something with more room to grow than the Myriads. Whatever you land on, ease into it and commit to a few days. Any different ski is going to have a different feel, but it's done wonders for my skiing to learn to adapt to different skis, and to learn what kinds of input always seem to yield good results (aka good technique). Sending lots of good vibes for the acquaintance process with whichever skis you land on, but I promise it's worth it in the end!
