I can't speak to the 150v4 but I can speak to the 150v2 against the 160 or 180v4. I've heard the 180v4 and own the 160v4. I also owned the 150v2 for 11 years. The 150v2 is light years behind the 160v4. The 180v4 also sounds great. You can read my review for the 160v4 on the 160 product page for more info.

As for the M22s vs M5, I believe you have M22v2 circa 2009. The M5 has a host of improvements that will give you improvements in EVERYTHING. I would expect even the M3v4 to sound better than the M22v2 because the M3v4 sounds better than the M80v2 which I owned for 12 years. You can read my review on the M5 product page.

As for using the M22 for a center, I don't know if the M22v2 would sound better than a 150v4. I can tell you I compared an M3v4 against my 160v4 and the 160 sounded better by a long shot. Much better mid-range, a touch better on highs and vastly better lows. There was no significant audible difference in off-axis response. There is something to be said for improved bass performance on the centre. I alternate between 40Hz and 60Hz on my centre crossover depending on material. I find these crossover settings sound better than 80Hz. An M22 can't go down that low.

I'd also like to point out v4 speakers like the M3 and M5 will give you a holographic-sounding soundstage when placed properly in the room. The soundstage will appear behind the speakers which is as it should be and images will appear with space in between as if the performers are right there. Instruments are also more faithfully reproduced. Transient response is also much better resulting in improved micro and macro dynamics. You will be far more satisfied emotionally with the v4. While the v2 and v4 look similar, they don't sound similar at all.