LR5 has brushable healing and cloning tools so you're no longer limited to a circular dot - but it will always be slower than Photoshop because the processing you apply in Lr is *not* changing the pixels in the original image. Adjustments are applied 'live' every time the photo is displayed. If you're removing a couple of scratches you won't notice, but cleaning up a mass of dust bunnies or a flock of birds and things will slow down.
It's important for new customers to remember this - fundamentally Lr is a catalog system, not a photo editor. Users get confused that images have to be 'imported' before anything can happen and it won't just browse through folders like Photoshop or DPP, but that's the entire point - it doesn't edit the photo files on disc, it builds a database of what you want changed; then exports or prints a copy when you're ready. If you process your photos in another application (DPP, Photoshop, etc) then Lr's database may still have value as a way to organize and search for your content, but if you prefer to keep things in a disc folder structure so they can be quickly-grabbed into other software it may not. To be frank, Lr prefers you to develop and touch up your raw files entirely within Lr, and only resort to a bounce through a 'conventional' editing program if absolutely necessary. To preserve the original file, Lr will make a copy on disc when it's sent for external editing, so you'll end up with two copies in the database (and two files on disc).
Think of it as Camera Raw with an SQLlite database bolted on the front that remembers what you did with the sliders, and resets them each time you view that photo. The advantage is that your original CR2/DNG files aren't at risk of corruption or overwriting, the payoff is that everything is 'virtual' until you export a copy. There's no "Save" menu in Lightroom!
Well, all being said...if you're doing things "non-destructively" in Photoshop, you're working with your RAW images as smart objects, and aren't making any changes directly to them there either. It eats up a bit more space and RAM/CPU, but you really should likely for most things be working with smart objects and layers...so that you can come back and redo something if needed later....so, in that case, it would be like you described working with LR.