I have to say immediately that I have not used the ADSL modem in this router, so I cannot comment on this function. I connect to the internet via another router, but the WRT320N is actually cost-effective as a 4-port gigabit router and wireless access point.
The unit is very neat; its shelf presence is unobtrusive and the indicator lights discreet, i.e. it is not a blue night-light, like some peripherals these days. I have not carried out quantitative tests, but the router performance certainly feels up to the mark and the wireless speed and range are more than acceptable.
I did have a slight problem on installation, which was no fault of the router, but necessitated talking to Linksys tech support. In the UK, Linksys support is provided via a premium rate telephone number, whereas in most other countries, a free phone number is available. They have discontinued support via email. I eventually used the live chat facility, which does work well provided you have a knowledgeable technician on the other end.
In the event, it took three goes - the connection dropped twice - and the third technician I spoke to identified the problem immediately.