Is this the bike you're on about?
Googled the bike you mentioned in your post but can't remember seeing what came up on image search on TUF.
If you're gonna get a bike i highly recommend a spin bike over the other exercise bikes, they just feel more like a genuine bike, replicating the road/hills moreso than a exercise bike.
They differ inprice from $200 to $1000 but i've ridden onthe $200 ones and if you find the right brand they don't feel cheap, i've sat on one for 2-3hrs of cycling and not had any major discomfort.
As for cardio - yes they are good for a cardio workout, but like anything in life you only get back what you put in... and with the inhouse exercise equipment it can be somewhat de-motivating whereas running/cycling outside on the roads if you don't cycle you don't get anywhere, in your house you ain't going anywhere anyway... so try things to occupy your mind such as loud music