I found this company on Google and contacted them to see if I could get a fairly (within 2 weeks) last minute booking. They got back to me quickly and we're able to help me book the summit. The entire experience was well run. From pick up at the airport to the experience climbing, everything was easy and as they promised. I didn't do a lot of comparison so it's difficult to say if they are the best or best prices but I found it very professional. The hotel and hut accommodations are very basic but absolutely do the job and are as advertised.
The guide they booked me, Zeeron, was fantastic and I highly recommend asking for him.
Regarding the actual hiking experience, everything they listed on their site for prep was pretty accurate. Take as little as you can as it's a tough climb and you'll be thankful you packed light.
There wasn't a spot available for the Via Feratta but they advised me to check in with that company when I got to base camp and I was able to book a walk in spot.
I would recommend them if you want an easy, all inclusive service for hiking Mt Kinabalu. Three only reason I didn't give 5 stars was because they were much slower responding to some of my follow up questions after I paid for the booking, but they did get back to me with good answers after I followed up again.