SPX/Security Chimneys pellet vent - any opinions?

Picked up a used Fahrenheit furnace today. It came with some of the venting I'll need, but not all. I have a 4 inch cleanout tee, a 3 inch section that connects the exhaust outlet to the cleanout tee and a few 2 foot sections of 4 inch venting. And a couple 4 inch type B elbows, which I already threw in the trash. It's made by SPX/Security Venting (P/N on the 2 foot sections is 4SPL24), which appears to be a division of Lennox Hearth Products.

Without dragging on, is it worth it to keep what I have and get the remaining pieces I need of the same brand, or should I replace it all with something "better" such as Duravent? I used Selkirk when I installed my insert years back. I'm not opposed to buying all new, but if I can save what I have I'll use the extra money to buy more pellets.

I have secutity on my pellet boiler and on a pellet stove. Works fine for me. I did the install and had no problems with leaks. I think the newest version has silicon gaskets so security no longer recommends adding a bead of silicon to the joints. Only problem I have had is not many stove dealers carry Security in my area and I have not found a web source. I understand Security agreed to be purchased by Simpson/duravent at the end of 2012 and Simpson claims it will continue to make security in Canada.