There's still a fanbase for close air support aircraft that go into battle slow, low and with a large bomb-load. The A-1 Skyraider is usually cited as such an aircraft, and the more modern example is the A-10 Thunderbolt II.
The "slow and low" part leads more or less directly to a good endurance (persistence over the battlefield), good observation and identification possibilities even without expensive sensors and a good accuracy even with "dumb" (unguided) munitions.
Much of the nostalgia is actually about the use of propellers, which are more efficient at low speed and low altitude than turbofans - and propeller engines also offer a good potential for long endurance.
Both the Skyraider and the Thunderbolt II are U.S. aircraft, and I'd like to present another example of a very impressive ground attack aircraft that followed the "low and slow" recipe: The Ilyushin Il-10.
The Il-10 was not only armoured to protect all vital components and crew against ground fire with machine guns, its integral armour was even capable of resisting 20mm HE shell hits!
The high degree of protection and a good armament (barrel weapons, internal bomb bay and external bombs) that even included cluster bombs with HEAT (shaped charge) warheads qualified it as a dangerous ground attack aircraft. The overall bomb load wasn't exceptionally high ("only" up to 600 kg), but reflected a practical and usual quantity. The range and endurance weren't exceptional either; the aircraft was rather meant for multiple sorties per day.
Well, why would I be so keen to present this historic aircraft?
Ground attack aircraft were in need of survivability against hostile fighters back in the Il-10's time.
The Germans of WW2 had to turn away from Ju 87 to their fighter model Fw 190 as primary ground attack aircraft (Fw 190 F series) because of the pressing need for air combat survivability. The result was a moderately effective, moderately protected ground attack aircraft that could double as interceptor (air combat against hostile fighters was to be avoided because of the armour weight, reduced armament and seemingly endless supply of hostile fighters). The use of a more dedicated ground attack aircraft (such as the Hs 129 B) would have imposed a requirement for escort fighters, which was less efficient.
Skyraider and Thunderbolt were never really survivable against fighters although they were capable of frustrating non-surprise attacks with tight turns. They were only employed in battle with air superiority.
The Il-10 solved this conflict by being an exceptional aircraft in ground attack AND a very dangerous opponent in air combat. This combination - not its relation t the Il-2 - should forever guarantee its fame and the fame of its developers.
On the whole, the test results proved the soundness of the concept. The optimum combination of powerful offensive and defensive armament in an armoured attack aircraft with high speed and good agility not only allowed effective multiple missions to be flown, but permitted the Il-10 to engage all types of enemy fighters in combat. [...]
During a short lull at the front, Lieutenant Colonel O. Tomilin [...] trained his Il-10 pilots in ground attack. On his initiative a simulated aerial combat was staged to enable them to study air combat tactics. The 'opponent' of the new' attack aircraft was an La-5FN fighter [...]. The Il-10 was piloted by Captain A. Sirotkin and the La-5FN by Hero of the Soviet Union Captain V. Popkov, a well known ace with 37 victories to his credit. By the end of the war Popkov's score had increased to 41, and he was awarded with a second Golden Star of a Hero of the Soviet Union.
The mock combat took place at low and medium altitudes, both pilots turning and using complex manoeuvres. Only after sharp and energetic manoeuvring did the fighter manage to get close to the Il-10's tail. Conversely, the La-5FN was centred in the crosshairs of the Il-10 gunner's camera more than once. Immediately after landing Popkov said: 'It is a good attack aircraft, almost a fighter and a deserving rival for the La-5FN'.
It is interesting to compare the Il-10 with the Luftwaffe's Focke-Wulf Fw190, which was in widespread use as an attack aircraft by the end of the war. [...] Its speed at low altitude, where it is best compared with the attack aircraft, was 9.3 to 12.4mph (15 to 20km/h) higher. After its bombs had been dropped the Il-10 was barely inferior to its rival in horizontal manoeuvrability, although it was inferior vertically.
"Soviet Combat Aircraft of the Second World War, Vol. 2", Gordon/Khazanov, p.57
The German aviation industry had never managed to even come close to such a quality air combat-capable ground attack aircraft (the Hs 123 came close to it during the period of its short pre-war production run). The Luftwaffe was indeed lucky that the Soviet battlefield air defences proved to be feeble by comparison (beyond machine gun range) and allowed the employment of a lightly armoured fighter-bomber.