Hey that looks like my bike! I have a 2005 Bighit FSR. These guys are right, 8 years makes it a tough sell.
Frame:
Personally I am not worried at all about my frame lasting 8 years, I know it will. I tend to crash a lot and this frame can take a real beating. Its just plain overbuilt, which is good for beginners. Im still running a lot of stock components, original frame bearings are still perfect. This frame has more suspension adjustment than most so it is versatile. Three different spring progressiveness settings, and four head angle / bottom bracket height positions. I bounce between stiff and steep, or soft and slack depending on the trails.
Weight:
Weight is certainly a weak point, I pedal this thing up lots of hills and my friends kill me. Stock, bike was 44 lbs. I have lighter cranks, pedals, and seat now, but heavier tires. 43 lbs now. BUT, you are looking for a DH bike and 44 lbs feels real stable at speed. I don't like my friends 27 lb stumpjumper because its squirly compared to this.
24" Tire:
Its slower than a 26 in the same way a 26 is slower than a 29. Larger tires roll over small ruts more smoothly. One advantage, for a given wheel/tire combo, it is noticeably lighter in the back than a 26. That said, I can take switchbacks and tight turns better than anyone I ride with. I can't be certain its the tire size, but my style has come to take advantage of the 24.
There are various opinions about the stock components, good and bad. Heres mine:
The truvativ cranks did me solid for 5 years, then one day I got way too muddy and wet. Bottom bracket started to fail after that. Replacements can be cheap though.
Not sure what brakes those are, but they look similar to Hayes 9's. Mine are still all original and plenty powerful. But I had to tear down and clean the calipers to fix sticking pistons. No rebuild kit, no money spent (besides brake fluid), just time. Wheels are rock solid, never had to true or tighten spokes, hubs still smooth and rigid. There are mixed reviews here, but all wheels have bad reviews like this "broke first ride, do not buy!" I currently have the same rear tire too, kenda nevegal, very good.
I paid 1400 for mine brand new. If I came across this I think a good deal would be $4-500 and I wouldn't pay more than $600 if its in top notch condition. Look it over closely!
So, yes it is a great beginner downhill bike. The deciding factor for you should be, how much maintenance and wrenching are you able to do? I have saved myself a lot of money by being able to maintain the bike myself! And obviously older parts need a bit more care than newer ones.
For reference, I ride all mountain, freeride, and downhill trails, enjoy small-medium jumps, my local trails have lots of 3-6 foot drops to flat, gnarly rock gardens and have done some urban jumping as well.
Ryan