Yes, the depth of field on this lens is small and fixed.
The 3 big issues with the lens you have to learn to deal with are:
1) hard to focus and to get as sharp as possible. Doable, but not easy.
2) shallow depth of field
3) funky donut shaped bokeh on reflective objects
I think, if you are on a budget, this lens (Mirror Reflex in general) is a pretty good deal. When I bought mine a few years ago, budget dictated the purchase. I wanted more reach. I got what I wanted. It is not my favourite lens and I seldom use it any more. Mostly pull it out for fun now.
I picked up the Nikon version. You do NOT need to spend the money, get a cheap one, it will perform just as good if not better. I wouldn't drop more than $100 on this lens and this is strictly for fun. Don't expect NatGeo quality images.
These lenses are light and easy to carry and use. YES, you can hand hold them. Hi ISO and hi shutter speeds on a sunny day, no issues. 3 of the 4 images I posted above are hand held. The moon shot is on a tripod, almost impossible to hand hold that, especially with a TC on it.
TC greatly degrades the image quality. However, for a moon shot, it is worth throwing it on and experimenting. Took a lot of pics of the mood with it.