Ok, deep breath. Remember you're spending a lot of money and taking some time to research is part of the process. If I catch myself getting rattled, indecisive or feeling a lot of pressure, sometimes its good to remember that its not a life or death decision. If its not clear, do some more research or just take a week off from doing anything about the kitchen.

First point, your carpenter can assemble and install any of them. Don't worry about that.

I have Scherrs and they are rock solid. They are better much constructed than ikea. You can get any size of anything and not pay more for it. You order sample doors to see colors.

There are a couple of things I wish ikea would improve in their cabinets, but they are likely better than jsi (more below). The cabinet size selection is poor. Their cam locks aren't the greatest, neither is the particle board. If put together and installed well, they should last a long time. Their drawers are fine. You can do something blended by getting scherrs to make the odd cabinets and your drawer fronts, trim pieces and doors for ikea cabinets. They know how. You can have ikea-cherry.

From the published information on jsi's site, its impossible to tell how the cabinet is built. So I have just two bits of info to go on.

I've seen the insides of a couple of brands of chinese cabinets and they were pretty crappy. The outsides looked nice, but the drawers and cabinet were constructed poorly. These remind me of those, but I could be wrong.

You'd lose a lot of potential storage space in drawers because of the frames. Click the picture with the drawer extended and you'll see what I mean - the usable height of the drawer is a little more than half of the height of the drawer front. Also, the "dovetail" drawer only has three pretty chunky dovetails and visible sanding defects. The surrounding doors have stain blotches. This is what they photographed to show you how wonderful they are...

Diamond is a problem - they are very pretty and have a large selection of sizes and types. The way the cabinets are made - the dimensions of the pieces and the way they are assembled - isn't very good. So, as an every day quality measure and completely unfair I might add, I've never seen a diamond display intact and I've not seen an ikea built-in cabinet display falling apart.

YMMV.
hth

bmore touched on pretty much what I was going to say. I was going to put option three out there. IKEA boxes if you want inexpensive framless with great hardware and Scherrs doors/drawers.

I came _that close_ to going with JSI, I was impressed with their plywood boxes and solid doors, but fortunately as I waivered in my decision making, I visited another shop that also had a display of JSI (not where I'd first seen them and nearly purchased them) and at this shop I noticed their drawers on a full-overlay display were crooked, so were some of their doors... to make a long story short, it turns out that JSI doors and drawers have a very limited ability to be adjusted once they become crooked (which happens over time). They are impressive at first glance -- just maybe not what you want to live with if crooked drawers and doors would bother you (and with full overlay it would affect functionality as well).

I'd suggest gong to a shop that carries different brands (as well as JSI for comparison),ask to see a maker with full extension slow close glides on the drawers as well as different types of hinges and ask them to show you how you can adjust them (make them show you (it only requires taking the drawer out and or using a screwdriver on the doors). It's highly educational, and well-worth your time in making your decision.

In the end, we ended up paying only about 20% more to go up to a much better brand that we've been very happy with.

Good luck,

Kris