i have owned pairs of 4041s, 4051s, 4040s, and 4050s. the only one of those i did not particluarly care for was the 4040 - a tad bright for my taste - and this is typical of my experiences with single capsule LDCs - invariably, dual capsule LDCs offer a larger, more open sound (the neumann TLM103 (yuck) vs the U87 (ahhh) is a perfect example of this).
the 4041s are one of the best buys in SDCs on the market.
the 4051s are even better - simply superb, especially for the money, and they are currently my main SDCs (and i have owned DPA4011s, 4006s, schoeps cmc64s, km184s, m300s, etc, etc).
the AT4050 is one of the most solid affordable LDCs you can buy, and works on literally any source - i use them all the time both in the studio and as flanking mics (in omni) for chamber music. smooth, huge and open sound.
i highly recommend the AT4050, the AT4041s, and the AT4051s.