I like a stiff soled shoe. My first “stiffish” shoe was a Five Ten Sam Hill Impact, which worked well until it got wet enough times that the cardboard insole stiffener gave up the ghost, at which point it was not all that stiff. I upgraded to a Freerider, then later a Baron, all for naught as the Five Ten flats shoes all seemed to be too soft. I thought I found a winner in the Shimano Am 41, but it was trashed and floppy in two months of riding, so I decided to make my own shoes.
I have now re-made three pairs of shoes, starting with softer clipless mtb shoes, I have my local repair shoe shop grind down the outsole, then glue on a crepe rubber midsole followed by a vibram outsole. Some of my project shoes have worked out better than others, it’s tough to find a clipless shoe that is soft enough for flats riding, esp after adding two layers of sole.
For the past six months I had been riding a pair of modified Specialized Tahoe, a recreational SPD shoe that is considered a beginner clipless, so it’s soft for a clipless shoe, but still far stiffer than any flats shoe. I liked the shoes okay, they work pretty well and have worn fine, but the flex pattern is just not quite right. Being designed for clipless with a full length stiffener, they are stiff end to end which makes them kinda like walking with wooden shoes, but they do put th epower down and keep my feet well supported for long rides
So after not finding the right combo of shoe and resoling, I decided it was time to look for a ready made shoe “again”. Previously I tried a Five Ten Maltese Falcon, a sticky soled spd compatible shoe. They looked promising, but when I test flexed them, the fiberglass sole stiffener snapped in two. After that experience I was kinda put off by clipless compatible shoes with fiberglass stiffeners. I though that all of the Five Ten clipless compatible shoes were built this way, but that is not the case. I was told by Five Ten that the Hellcat, Raven, and Cyclone are built with a nylon stiffener.
So I ordered three shoes from Zappos as a test: Five Ten Sam Hill Impacts, Teva Links, and Five Ten Hellcats. They arrived overnight for free shipping and free return; ya gotta just love Zappos for service 
First off, I tried on the Links because I had always wondered if they were any good. Suprisingly they fit well, were well made, and relatively stiff. Not stiff enough for my needs, but in contrast to other popular flat shoes, they held their own. If I were looking at Impacts, but wanted a less burly shoe similar to the Freerider but with some stiffness, the Links would be my first choice.
Next I tried on the Sam Hill 2, which are just a brightly colored version of the Impact Low; I had a pair of Sam Hill a couple years back. These were about as I remember them, lots of bulky rubber, high arch area in the outsole, and not as stiff as you expect from all that rubber. In all honesty, the Teva is just as stiff as the Impacts, lighter weight, less bulky, and better made. I think Five Ten could upgrade this shoe, but for 2013 it is the same shoe with a slightly narrower profile; oh well.
So then I started playing with the Hellcats, which are essentially a beefed up, stiffened Baron, with a velcro strap, and an spd compatible 3/4 length “nylon” stiffener plate. The cleat area is covered by a flexible metal plate covered in sticky rubber, so the sole is grippy in the cleat area, unlike most clipless compatible shoes. Suprisingly, after considerable flexing and twisting, I was unable to damage the midsole; I had to try 
In contrast to a shoe like the Impacts, the stiffness is night and day different, where the Impact is like a lightweight hiking shoe, the Hellcat is like a stiff hiking boot. The stiffest flex is nicely centered over the midfoot and forefoot, while the rear portion of the shoe (behind the arch) and the toe box (in front of the cleat cut out) has a softer flex. This combination of flex patterns allows the shoe to be supportive while riding and comfortable for hiking. The Hellcats weigh about the same as the Impacts, even with the cleat area cover. Fit is very similar to the Barons, maybe a tad less roomy though the midfoot.
I thought about replacing the cleat area cover with a softer piece of rubber, but it sits below the sole and really doesn’t seem to change the flex or
traction, so I’ll leave it for now. In terms of sole grip and “softness”, the sole is harder than the Impact, but made from Stealth rubber, so just as sticky as other Five Ten riding shoes, so I had no problem getting grip on pinned pedals, in fact it was better than my remade shoes, which made me smile
Durability and long term ride review to follow, in a few months…but so far the Hellcat shows promise.
