I have been using aircel since the past 3 years. I ported from docomo to aircel mainly because of RC 24 internet pack provided by aircel which would give one month of 150 mb data. I found it useful because I had wifi at home and used mobile network rarely when there was a power cut or when I needed it outside.
The 3g speed provided by aircel is really good and is comparable with airtel’s 3g speed.The major disadvantage with aircel is there is no proper connectivity in city outskirts. Aircel is the best network if you have wifi at home and want mobile internet at cheap price wherever required.