I've purchased quite a few styles as a short cosplayer who tends to try to add a few inches height-wise (Bloq Hi, Qozmo Hi, Creep) and for casual wear (Qozmo Chill, Lala, Slayr Camo reflective, and a couple others that aren't available but weren't designed by them).
Sizing & Comfort:
Their shoes run true to size but tend to be slightly narrow, so wider feet folks should get a size up for comfort over a long wear time. The back of your ankles/legs may get torn up from the back of the shoe chaffing against your skin over time (I've had this happen on Chill, the Slayr Camo, Creep, but less so with the Qozmo Hi), so if you're planning on walking around for more than a few hours, make sure there's a buffer where the top of the shoe contacts your leg.
Admittedly, none of these shoes (that I've owned) are very breathable due to the materials used, which is to be expected, so it's nothing to really run home about. You may not find your size during big sales promotions, so definitely shop around in advance.
Their platforms are comfortable to wear since Bloq and Qozmo has a slight curve to the platform. Creep feels the most inflexible to wear since they're pretty flat on the bottom despite being significantly shorter in terms of added height. Always be careful on slopes and stairs because the higher platforms can and will split on a grade as simple as an entry dip, yet somehow be perfectly fine if you roll your ankle about 15 times. They can be glued back on, but I've personally resorted to contact cement since I usually wear them all day and need that extra placebo of safety.
Their sneakers doesn't really hold up as nicely as it should, especially if you're walking around frequently. This especially occurs with the Chill series--the eyelets are prone to coming off, the leather that the lace loops through can snap where your toes naturally bend, the shoe glue can separate from the sole from bring used too much within the day, and it's possible to accidentally scape and damage the outer leather if the top three eyelets scrape against your opposite shoe. These shoes definitely aren't made to handle long periods of walking around compared to true skater brands. Their Lala series holds up the best in my opinion (especially the non-vinyl ones) as they're both equally comfortable and flexible. If you like wearing loud shoes, you'll definitely attract some eyes since their colors are incredibly vibrant.
Customer Service & Shipping:
Using their customer service is hit or miss, and they tend to take awhile to respond. During one of their flash sale promotions, the site didn't authorize their advertised promo code and it took over a day for them to get back to me, but luckily, they allowed me to use their promo code despite their response being after their flash sale timeframe. Understandably, others haven't been very lucky in their specific instances.
I don't worry too much about their order processing since I purchase when their order volume is likely to be higher, and I expect it to take a few days. However, if you're on a short time frame, you may want to pass and go through another retailer, especially for customers that don't live in California. They tend to create their shipping labels very early but don't dispatch orders to mail carriers the same day. This has occurred for most of my orders.
I tend to purchase their shoes when they're on at a discounted sale price except for the Qozmo Hi as they tend to be more permanent than the others, but they do their job. They just require a little more care to last long, which might not be very appealing to customers that are used to shoes that can survive an apocalypse. So far, I personally find most of them comfortable to wear (until the chaffing starts if I'm wearing the wrong socks). As someone who can't wear extreme heels for more than like 20 minutes, their platforms are a godsend, and I would personally recommend them for adding some extra height for cosplay and don't mind a chonker of a wedge. Order them in advance in case processing and shipping time is not on your side.