I've been using a WRT610N that looks very similar to yours, for about 5 years now.
It meets all my needs, and works amazingly well.
BUT... looks can be deceiving, as my model has some BIG ADVANTAGES over yours.
On your model I was just noticing that the specs say the Ethernet ports on the back can only run at a maximum of 100 Mbps if I am not mistaken?
That's not good!
For me 100 Mbps would not be fast enough. I personally demand/need at least 1 Gbps (1000 Mbps) over my home network's Ethernet connections.
That's because I've used Ethernet cables to hardwire several of my computers directly to the router, to share/transfer large files rather frequently.
Your router's slow Ethernet speed means that if someone has 300 Mbps Internet connection, and plugs their Ethernet cable into your router, they will only get 100 Mbps, even though their Internet provider can serve an additional 200 Mbps.
So in that scenario, your router becomes the BOTTLENECK, preventing faster communications, because it's fastest possible transmission speed is only 100 Mbps.
ANOTHER BIG PROBLEM with your router, according to the specs that you linked to, is that it is using the older and MUCH SLOWER 802.11g, instead of the newer 802.11n.
If I remember correctly:
802.11g runs at about 54 Mbps. 802.11n runs at about 600 Mbps.
802.11n can be 10 times faster!
So again, if someone has an Internet provider connection that can handle 300 Mbps, but the router's wifi can only dish out 54 Mbps... then the router is the BOTTLENECK.
OTHER PROBLEMS WITH 802.11g WIFI:
Another big issue I would have, if I had to use your router, is that 802.11g can only work at 2.4 ghz (and can not work at 5 ghz) if I recall correctly.
2.4 ghz is a VERY CROWDED frequency range. Crowded conditions dampens performance, reducing your ability to achieve even the 54 Mbps.
So if your region's 2.5 Ghz spectrum is CROWDED, then you are not even going to get 54 Mbps.
There are several apartment blocks where I live, and something like 15 strong WIFI SSIDs in the 2.4 Ghz range, and only 2 SSIDs in the 5 Ghz range (including my own).
This means that I, and that other person, pretty much entirely have the airwaves to ourselves!
I don't know who this other person is, but we naturally spaced our channels apart, so we don't even come close to each other in the 5 Ghz range, gives us nice, quite, smooth, dedicated airwaves!
INTERESTINGLY: Microwave ovens also interfere heavily with 2.4 Ghz. For example, in my kitchen I have an xBox 360 (2.4 Ghz), and kitchen computer (5 Ghz).
When I turn on the microwave oven, it beams a bunch of noise at around 2.4 Ghz, and the xBox wifi cuts out, but the kitchen computer's 5 Ghz seems unaffected.
ALSO...
802.11g can impact your ability to connect other wireless devices to your network if you ever wanted to, such as wireless security cameras, etc...
Running an HD camera on 802.11g will probably suck up what little of your wifi's noisy/crowded bandwidth is available.
Trying to copy the occasional large file on 802.11g would probably take a while.
IN SHORT,
Your current router is probably just fine... but only if:
1) If your local 2.4 Ghz spectrum is NOT crowded...
2) Your computer/router is not too close to a microwave oven that runs frequently
3) You don't connect any computer/devices to the router over Ethernet, and expect to copy large files/transfers.
4) Provided that your current Internet provider connection is only about 50 Mbps or less.
AND DON'T FORGET:
If you pay for, or upgrade to Internet that is faster than 50 Mbps, and don't upgrade your router, then you are wasting your money!
Again, that's because your current router will not be able to take advantage of any of that extra bandwidth/speed.