Got one this summer. Was actually looking at the DX-R8T as a desktop SW receiver ( the Icom R-75 having been recently discontinued, the Alinco is about all that remains). However, for a few bucks more, went with the DX-SR8T transceiver. Have not used it much transmitting on the ham bands but as a receiver it has been great. Fairly intuitive and easy to use with just a simple menu that does not require constant manipulation. Real happy with it.
IMHO you can't go wrong with either the Alinco or Icom for use as an entry level hf rig. The IC-718 has been around for a long time and there are a ton of them out there so hopefully someone who has one will respond to you. Had looked at the IC-718 myself before buying the DX-SR8T but the Alinco was a bit less money and did everything to meet my needs so went with it. Do a side by side comparison of all the specs and features and go with what you feel is best for you and your style of operation. Ultimately only you can decide what is best for you. Good luck with whatever you choose.
I got my DX-SR8T from Ham Radio Outlet and also got the LDG AL-100 to with it from them. I have had good reports with this radio. I got mine to use until I get the dot problem fixed on my Kenwood TS-440. LDG stopped making the AL-100 but HRO still has some. The DX-SR8T doesn't have the whistles and bells that some radios have, but for the price I don't think I went wrong getting this radio. I am going to give mine a workout this weekend at Skywarn Recognition Day
If you have antenna questions, it would probably be best to scan the threads in the Amateur Radio Antennas forum or start a new thread there. Antennas are generally not specific to any particular model of radio, except maybe for rubber duck antennas on handheld radios.