I would love to ditch Eagle PCB for a tool like this. Eagle is awesome, but as a hobbyist I don't use 70% of its features. From a quick look at circuits.io here's what I would want in order to make the switch:
1) Let me import my Eagle components
2) Give me more control over grid sizing
3) Autorouter!
I'm also interested in seeing the fabrication prices. Right now I use batchpcb.com (a Sparkfun service). There really aren't any other good options for printing a single PCB.
We are currently working hard at integrating with the octopart api. We aim at building a huge crowd sourced component lib, so you will never have to enter components again.
Grid and measurements are definitely on top of the list.
Autorouter is a bit lower, but want that. We will probably first do some form of assisted routing.
At this point you can download your gerber files and send them to a manufacturer of your choice, but we are working on integrating with services like BatchPCB.
Assisted routing would be way more useful (and probably easier to implement) than autorouting. Also, it would be great to have a versioning system that could pull together the good bits from different attempts at routing.
Check out Advanced Circuits, they have a barebones PCB service that isn't too expensive for ordering test boards and one-offs. Turnaround is one day plus shipping. And they send you popcorn with your order for some reason.
OSH Park (formerly known as Laen's DorkbotPDX group PCB order) is very popular for prototypes in the US maker community (look for the trademark purple PCBs), and at $5/inch^2 with free US shipping it's cheaper than batchPCB for smaller boards, in addition to getting 3 copies of the board for that price. It's very high quality and it's all done at a US fab house with the 2-layer batches sent out every 2-3 days and then shipped US Mail, so if you're in the US it's pretty fast for the price.
And for pure price, Seeed and ITead (both are rumoured to use the same PCB fab) are very popular with their $10 for 10 copies of a 5cm*5cm board service. The quality is reportedly much more variable with these guys, and the shipping takes a lot longer to reach the US, but you can't beat the price. For the rest of the world, the shipping from China is probably cheaper and faster than from OSH Park, so unless you need the quality of OSH Park this is probably both cheaper and faster.
I second the recommendation, I've been using lean's service for a rather long time (I've go boards from back before he worked out the right purple color) and I've always been happy with the speed and quality, it's a great service.
I had a board assembled recently ( https://0xfb.com/shop.html ) by bittele ( http://www.bittele.com/ ) and was very happy with the result and the process. In the US, there is screamingcircuits as well, they have faster turnaround if all your parts are sourced from the US, but cost more.
1) Let me import my Eagle components 2) Give me more control over grid sizing 3) Autorouter!
I'm also interested in seeing the fabrication prices. Right now I use batchpcb.com (a Sparkfun service). There really aren't any other good options for printing a single PCB.