Not bad advice, but there's nothing inherently unsafe about older aircraft. Most low-cost carriers outsource their maintenance to third-party facilities, which operate under the same FAA or EASA regulations that in-house shops abide by. These are often the same facilities that larger carriers end up using for surge support when necessary. The pilot experience thing is a valid concern with LCCs, although you will typically find your youngest / least experienced pilots at the regional affiliates of major carriers.
Speaking as someone who is deeply involved with aircraft design / modification work, there are two easy things I recommend to everyone which significantly increases the margin of safety when flying on commercial carriers:
1. Fly on airlines from English-speaking countries when possible. English is the universal language used by ATC worldwide. There are numerous documented instances of accidents being caused by pilots and controllers being unable to clearly understand each other due to language barriers... pilots thinking they were cleared for takeoff and weren't, controllers not understanding a critical request that pilots were making, etc.
2. Do not sit in line with roughly the front half of a turbofan (jet) engine, or in line with the propellers on a turboprop aircraft. Uncontained fan disk, turbine blade, or prop blade failure happens occasionally, and can easily send metal shrapnel into the fuselage. Aircraft with tail-mounted engines are of particular concern here, due to the proximity of the engines to the cabin. The last couple of rows on the MD-80 should be avoided at all costs IMO.
