1

You can choose another bus:

1: Sapaco Tourist 500 Nguyen Dinh Chieu Stress, Ward 4, Dis 3
2: MaiLinh Express 292 Dinh Bo linh Ward 26 Binh Thanh District.
Ticket prices varied base on providers and season.

2

Mai Linh have ceased on that route for now.

http://www.thanhniennews.com/index/pages/20120813-vietnamese-buses-in-fierce-competition-with-cambodian-rivals.aspx

3

I think Mekong is still better than the other providers by Cambodian standards. I haven't taken the Giant Ibis but I heard it's quite good.

4

so we took giant ibis sr - pp and it was great. $13, so $1 more but brand new, clean, wifi, and 15 empty seats so we could spread out.

finally decided to stick with mekong express to get to hcmc and all was fine (good air, seats near the front, non-smelly in the back as far as i could tell)...until about 1.5 hours in. we had just gotten to the mekong river where we were supposed to cross and the clutch went out. so sat thêre for 2 hours (they told us it would be 1 hour) waiting for a replacement bus. they kept the ac on for awhile but then turned it off and we had to go sit in a cafe where it was hot but with a light breeze. too bad giant ibis doesn't go to hcmc!