I'm guessing the old one is the fully white with a single LAN port and single phone port. If this is so then:
The old and new are basically the same. Some things have happened with Digicel in the last 2-3 years and their signal quality has dropped. I don't know the technical specs of the two so I can't say why exactly. What I do know for certain is this. I had to switch my brother over to DSL from FLOW because Digicel gave him garbage. For years he was using the old model with no problems. Then 2-3 years ago the signal suddenly dropped and he was getting between 1-2 bars of signal. Thought that the device was old and purchased the newer model with wireless and same thing. Now the modem has not been moved from that spot in so many years that when we did replace it the dirt had made an impression where the device was. By the window. Elevated on a platform. They told him all manner of garbage from cloud cover to "recent developments in your area may be blocking the signal" or some other crap. Where he lives there's a clear sight of some mountains, a valley and the 4 houses that are neighbors have been there for ages. I have them both currently (giving one to another family member) and let's see what I can say..........
OLD MODEM
- Not slower than the new one once you get signal.
- Runs hotter than the new one under load.
- Can be used with a switch - has no limit (that I've seen) on the number of DHCP leases.
NEW MODEM
- Not any faster than the old modem.
- Runs cooler.
- Limited DHCP connections - I believe it's 5 wireless and 2 wired. Would need router for more.
- Has wireless.
- Looks prettier.
With all of that info I leave you to make your decision. Upgrading the modem isn't going to improve your situation. If you're not getting service try to relocate the modem. That's my best advice. If you want to be sure that the modem isn't at fault then take it somewhere into a town that you know is within their coverage area and use it. If you get better performance in the town then the problem is either where you have the modem or Digicel being "smart" as they usually are. If the performance doesn't change then you may have a faulty unit. Highly doubted though.
Knowing the solution doesn't mean knowing the method. Yet answering correctly and regurgitation are considered "learning" and "knowledge".