Yes, the interface can look exactly the same on the customer side, independent of what kind of technology you use for carrying the traffic.
Second, third and fourth generation mobile networks all have their different characteristics. For M2M/IoT it is important to remember that 2G is usually GPRS and EDGE, which means packet-data over the traditional GSM-grid. 2G is usually known as limited data rate. 3G is usually referred to as UMTS or WCDMA, with further developments HSDPA, HSUPA, HSPA+ DC-HSPA+. All of them are based on UMTS. 4G is UMTS-LTE (Long Term Evolution), an is a simplified architecture for mobile, based on IP-protocols, end to end.
Secure communication is best achieved by combining different technologies.
Com4 recommends using a closed APN for logic separation from other customers, and separating the communications from regular internet-traffic, at the same time as ensuring sufficient encryption by the help of mechanisms on the transport-layer (example: IPsec or SSL/TLS) and application-encryption and integrity-control.
The customer-portal has a feature “View Call History” where you at any time can see connections and attempts, including APN-name, timestamp and an error if it occurs.
Detailed logs that expand on this will be hardware-specific from device to device.