A2 Hosting is one of the leading hosting providers, and they have been for a number of years. Arvixe used to be very highly ranked, though they have fallen short in recent years, which is unfortunate. When looking at the two companies side by side, it is really not much of a competition at all. A2 Hosting is ranked far better by users, they serve more regions, they have more hosting options, and a more impressive list of features available. To put it simply, if you have narrowed your options down to these two hosting companies, A2 Hosting is the clear winner.
I accidentally deleted my entire website (my fault), and my backups weren't working properly, but they managed to provide a backup and support within record time. Saved me from a panic attack. Truly appreciate that! Some cons... More : a bit slower than my previous BlueHost, but definitely far less expensive. Also uses the latest MySQL on VPS only, not shared hosting. Less