I had a horrible experience with this company. They held my website hostage and required us to cease and desist because a third party accused us of illegal activity. Just that claim. No laws cited because there is no such law. And no chance to explain ourselves.
I've been using Aplus.net to host a production web site and as a test site for two years. Software offerings are pretty standard; service has been very good; support helpful when called. I can't understand the problems that others are reporting ..... I have seen some recent reviews that ranked the site lower than in the past, but my stuff has not been effected.
I've been hosted with aplus for a long time and their service is good. I manage my own server, but if I ever need support from them I get it. I can't tell about the malicious content, it comes as a surprise. But with regards to aplus being blacklisted for spam, I would be very careful of how some spam blacklists take their decisions. One my domains was blacklisted by SORBS after it was reported by someone who had registered in a forum hosted in that domain, after he received the only one email that's been sent to registered members...in FOUR years!