Well, for today's software, it kind of is slow. Its IPC performance is about 1 DMIPS/Mhz vs ~3.5 for the latest high-end ARM chips, which also have 3x the clock speed of RPi, and come in quad-core variety. Do the math. That's a 10x-40x delta. Of course such a board wouldn't cost $30 anymore, but they could still improve performance by at least 3x with another low-end, but more modern, CPU, even as single core, but even more as dual-core or quad-core. Even a single core Cortex A7 at 1.2 Ghz would be about 3x faster than Raspberry Pi (90 percent faster IPC * 70 percent faster clock speed).

Personally, I think they should wait until they can make a dual-core 1.5 Ghz Cortex A53 with 1 GB of RAM for $25, which may be possible by 2015, and maybe a quad-core 1.5 Ghz Cortex A53 one with 2 GB of RAM (and perhaps a few extra stuff), for under $50 (I would make it for $40-$45 so the total cost with shipping and whatnot still remains under $50 for most people, instead of going over that price point). A single core Cortex A53 at 1.5 Ghz (its stock clock speed) would be ~5x faster, and also 64-bit. By the way, Cortex A7 and Cortex A53 are both the true successors of the ARM11 CPU RPi is using, and they serve the same markets.

The $25-$50 market, is still probably their best market, since a lot more companies compete at the $100-$200 level.

Kind of slow, but the OP is talking about seconds in response time, something is going badly wrong. Software issues not CPU throughput. It doesn't help that IO is terrible, there is no point putting in a faster CPU without SATA and a bit more throughput overall.

They are in a great position for volume, so should be able to do better than the current choice that was suboptimal in so may ways. Not clear that the 64 bit stuff will be that cheap soon (plus porting code will take a while) but it depends when they are going to do something. Cheap is important.

i used to run Owncloud (php), which was ok for CalDAV and CardDAV, but the web interface was terribly slow. Now I run calendarserver for CalDAV/CardDAV (Python), which is fast for CardDAV (few data) and slow for CalDAV (a lot of data). I am also running Bittorrent Sync (binary blob, fast), and Time Machine backups (fast).

My conclusion: The Raspi is slow for serving with dynamic languages. Compiled stuff is fine.

As you would expect for a processor designed for embedded systems. Everyone trying to use this as a cheap LAMP server gets what they're paying for.