Should i get a new wireless router?

I got a NETGEAR router that is WGR614 v7. We had it for about 2-3 years and it worked perfectly for the the first 2 years, and at that time I only used it for my wii, then i got a DS and used it for that too. We eventually got a laptop, a PS3, and a 3D Tv that can use a internet connection for browsing and other things. Sometimes when guests come over they bring their PSP's, sometimes phones and use mywireless router. Since then the the wireless router started to not work at times and it messes up our gameplay. Sometimes the router makes things just really slow, and it gets annoying. Sometimes it works fine too. Idk I mean I still like it, but all that stuff happened like frequently, but now it seems okay since I did a system restore on the computer that is connected to the router. So can a WGR614 v7 NETGEAR router hande 5 things(sometimes more) to use its internet connection. Or will getting a new one make internet connection better, cuz I saw some New NETGEAR routers at bestbuy and it runs at GIGABIT speed a couple weeks ago and i was thinking if a new one should be better.