We're already at the point where smartphones are more powerful than low-end laptops (quadcore cpu, 3gb ram,...), so I think the performance shouldn't be an issue. This race to higher specs needs to come to a halt and manufacturers/devs need to increase the performance of the software. So I'd rather have a snappier experience with better performing apps and OSs, rather than having more functions/options with more error messages and crashes.
PC monitor:
20-24" is enough for me, I rather have more displays than one big screen -or- 27"+, as big as possible, no need for multiple monitors and annoying bezels?