As a freelance ERP software consultant I've been using Sherpadesk for four months and I can say I'm very happy with the service. It can create tickets via e-mail which is essential to me. It's even free for a one support account. It's possible to create a customer account/contact, support categories, custom fields, priorities, SLA, support portal, knowledge base etc. Remote assistance & live chat are also possible with a small extra charge. The system has very flexible reporting capabilities and the standard Time & Costs report works very fine for me. One drawback is that it can be somewhat slow from time to time. Last but not least it has a mobile application as well (I use Android). SherpaDesk is a full fledge support desk software and I can recommend it to anyone.