Don't know whether to buy a new imac

Question

I would be extremely grateful if some of you kind folk out there could help me in this quandry I'm having. I am considering buying a new mac because I am starting to feel the pinch as it were on general preformance namely speed on my old mac. It's a 17" flat panel iMac
CPU Type: PowerPC G4 (3.3)
HD 80G of which 56G is used
Number Of CPUs: 1
CPU Speed: 1 GHz
L2 Cache (per CPU): 256 KB
Memory: 768 MB Type: DDR SDRAM Speed: PC2100U-25330
Bus Speed: 133 MHz
It is also one of the models that came with the SONY DVD RW DW-U10A that well dosen't really work i.e. has never burned DVDs, now rarely burns CDs (music, data etc) and reads mabye 50% of dics put into it. On this point I have downloaded the instructions on what replacement drives to buy and how to install it if I was to go down the route of keeping that mac.
I, though not professionally use a lot of big and hungry apps. such as Garageband, Reason, Photoshop CS, Illustrator CS, Flash MX and iMovie and am going to start using Final Cut (probably Express) and Logic 7.
The mac I am considering getting after looking at bang for your buck is a G5 20" iMac 2GHz and mabye upping the RAM to 1G. I really can't afford a Power Mac Duel 2.3GHZ or anything in that range, what with having to buy a moniter as well.
So looking at the all the costs (i.e running my OS from an external HD, more RAM, changing the Superdrive etc.) involved is there any way of significantly improving my old mac to enough of a point so as to feel a real change in prefomance because at the moment things are really slow and sluggish.
Sorry for being longwinded and thank you for any advice.

Answer 1

I've heard that the new imacs have a trouble with overheating. My cousin has replaced his main board twice (under warranty). I don't know if this has been fixed (http://www.macnewsworld.com/story/45900.html).
The other thing to consider is Apple switching to an intel processor(http://arstechnica.com/news.ars/post/20050606-4974.html). Apparently people who have hacked the developer version of it to allow it to run on a non-apple intel machine reported that the system ran much faster than the G5 processor (http://www.wired.com/news/mac/0,2125,68501,00.html). If you can wait a year or more, then you might want to go with one of these new machines. Of course, you would be buying a first-generation system that might have a bunch of bugs.
I've also seen some sites(http://www.macworld.com/news/2005/09/16/daystar/index.php?lsrc=mwrss) where you can upgrade the processor that you have now to near 2ghz. If you want to invest a bit of money without completely changing your system you could look into these.