I haven't got a dryer at all - but would think the condenser means you use less energy and it recoups some of the waste heat from the exhaust gases.
BUT - which says this :
Tumble dryers, especially condenser dryers, take more looking after than just about any other appliance in the kitchen.
Heat exchanger
Heat exchanger
The heat exchanger requires regular washing to keep it free of fluff
Heat exchangers change steam escaping from your washing back into water, but tend to get clogged with fluff that is mixed up in the steam.
You need to clean the heat exchanger on condenser models at least four or five times a year and this is usually a pain to do.
Water reservoir
If you buy a condenser model, you'll need to empty the water reservoir just about every time you use the tumble dryer.
It's easier if it's housed in a drawer at the top of the machine, rather than down near the floor.
And it helps if the water outlet slides open and closed rather than needing to be screwed or pressed shut.
Lint filters
Door mounted lint filter
Don't let fluff build up in your dryer's lint filter
These trap the fluff whipped up in the dryer. To keep the dryer running at peak efficiency, you need to clean the filter every time you use the dryer.
We prefer filters that are easy to just lift from their mounting on the back of the door. Some other dryers make you rummage around inside the door opening to retrieve the filter.
And some filters are double sided, with hinges in the middle and tricky catches, which makes them twice as hard to clean.