Its generally better to use the chainsperday value for comparison/performance assessment. However, 3k PPS is similar to what you'd expect from a top of the line intel i5 CPU and some of the higher end i7's. So I wouldn't really call that 'low end'.

Using poor or solo mining depends only on how long you can wait between getting payouts. Its possible at around 3k PPS that you may now only find a block once per fortnight or less. However keep in mind that a block is currently worth a lot more thanks to recent interest: Right now a block of 10.10 XPM is just under $60 as I write this.

Although a lot of people struggle to understand/accept the variance inherent in solo mining blocks, my anecdote from my ~3k PPS CPU is that I have found about 1 block per week over the last month. However you need to keep in mind that difficulty has recently risen another few %. I have some slower machines that can go months without finding a block.

If you look through my comment history, or mikaelh's comment history, you will see discussion regarding the calculations you can use to estimate your mining capability.