We have been using RMS, both as a front office (for the three years) and channel manager for the 2 years we have been here and inherited from the previous owner.We now have UseROss as our channel manager (part of being with the Arra group) We are on the verge of switching over to perhaps concierge as it looks fairly similar to RMS. The cost of RMS is going up and they now want to lock people into a 2 year contract, so its time to move on!!
Provided you have a channel manager, they can connect you to nearly every OTA with whom you wish to be connect.
Yes you definitely need a front office system, it saves so much hassle and the chance of double bookings.It is worth the money that you spend each month. Its finding the one that gives you the support, at a price you can afford and one that you can operate.
Good luck