The biggest problem with the conventional RPTV bulbs is that most of them lose luminance slowly over their lives, so when they go out, it's at the tail end of poor performance. I know that LEDs will dim, albeit very slowly and not noticeably, and last as long as CRTs. Panasonic introduced LiFi lighting in their RPTVs last year, which are (supposedly) good for close to the life of the unit and (supposedly) do not degrade.
If you want to buy an RPTV, if it has a bulb (a few still do), compare the price of it to the LED/LIFI versions including at least 1 bulb (if not 2). Service contracts used to include replacement bulbs for cheap, but these days it's less likely that you're getting a good deal on them, if they're included at all.
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--Greg