Let's be fair here. The A1200 is just as likely to have cap issues as the A600.
On the other hand, the A1200 will do much more than the A600. There's no denying that the A1200 is a more-capable Amiga.
The A600 on the other hand, is very compact and has its charm. As ever, it all comes down to personal preference. If the A600 is cheap enough and you can afford the house-space, why not take it and have a play? Otherwise, give it a miss, knowing your A500 will do most of what an A600 can, particularly if you're thinking off getting an A1200 as well.