That's true. But I would really like to see how bad the original caps were ESR wise.
If that was a eMac (the one with known capacitor disease) or iMac G5, then a full recap (including the PSU) would be totally in order. I had iMac G5s that didn't boot into OS (just froze) that had just one capacitor blown on the mainboard.
Btw,
Few weeks ago, I had a friend phone me for advice, he just fully recapped a 2004 Samsung SyncMaster CRT 17-inch monitor as the picture was soft (slightly of focus, especially on the edges, and somewhat dim). Recapping made no difference to the picture quality whatsoever, and he was quite mad since he spent about $40 on capacitors and about 4 hours of his time.
Long story short, the culprits were both the worn out CRT, and slightly out-of-adjustment focus control on the flyback. I turned the focus control and made it almost perfect, but the image was still dim, and increasing the G2 (Screen) control made it just completely blur out. I said that it looks like the CRT is weak.
Later we took it to another friend of mine that used to own a TV repair shop not so long ago, and he put it on a CRT tester, which showed it was quite tired. He did a CRT cathode cleaning, it made it just a tiny bit better, later he tried with rejuvenation, but it didn't help.