The most common failure for any led system is driver failure usually due to electrolytic capacitor failure. Cheap chinese 2000 hour 105C 50V caps are often use to hit a the low price point required for consumer bulbs. Assuming the best case of 25V forward voltage, the driver would need to operate at 78C to get the common 25k hour claim. That is a hard temperature to reach when you are dissipating ~10W in such a small area. When you enclose the bulb, you can easily increase the operating temperature by 10C which would then reduce your life by half to 12.5k hours.
You shouldn't have to worry about the leds failing. Even at high temperature 25k hours is easy to achieve with modern phosphors.
In terms of CRI, all new leds are in warm white color temperatures have a CRI of at least 80 but the R9 value which renders red may only be single digits. Recently 90+ CRI versions are becoming available due to pressure from California legislation. These will have a R9 value of at least 50, which will make skin tones look more like filament type bulbs. 98 CRI chips are available, but its debatable if it matters at that point.
I bought some ">90" CRI bulbs recently, and they are simply excellent. The difference in color rendering is immediately noticeable to me. Recently in Ontario, Canada there is a electric utility sponsored program where you can get huge discounts on LED bulbs, to encourage reduction in energy usage, as supply is a big issue here in summer. I was able to get $8 off packs of 4 bulbs that cost $12 (at Costco), so $1 each bulb after discount. They are the best LED bulbs I have bought yet, and the cheapest as well. Luminous brand. Roughly the same deal on PAR20, GU10 and filament style candelabra bulbs as well. I stocked up.
These were so cheap that I immediately took one apart to have a look. The driver in these has no electrolytic caps, just 3 film ones ... AC line to a series fuseable resistor, cap across the line for noise reduction, then a bridge rectifier going to two more film caps as a reservoir. A driver IC and a small amount of other SMD circutry rounds it out. I assume that the driver circuit is specifically designed to work with high ripple on the raw rectified DC. They have seven 1 Watt LEDs, probably in series and having two die each. The LED board lights brightly at around 50 VDC, drawing about 100 mA at that voltage. I like this driver board, it looks better than most of the ones I've seen doing post-mortem exams on dead CFL and LED bulbs in the past.
I was thrilled to finally replace seven incandescent PAR20 bulbs in my kitchen with these LEDs. The only issue is that they are so bright I needed to install a dimmer. Bulbs cost $7 total, dimmer about $45. Energy usage down from 210 W down to maybe 10 to 20 W (I dim them quite low). These are frequently used lights, so I should see savings soon enough.