surely progress is a personal thing, and if you take all the variables like your previous sporting history (if any), how many hour per week you train and what your goals are there really isnt an answer that any of us can tell you.
your hr going down is not a measure of progress if you are going to try to beat your PB, i would think that your hr should be the same and your time improve, if your hr is coming down your not trying hard enough

a lower hr rate for an equal time would be indicate a gain in efficiency and/ fitness.
as far as swimming goes i couldnt swim even 50m a few months ago but now knock out 4k continuous swims once a week but i do swim about 10k a week - thats what i call real progress at a personal level for me but it takes me 1.50 to swim the 4k which isnt progress as far as the bigger picture goes. i got into tri pretty late in the season last year and I can still remember putting 14minutes down in my expected 400m swim time - at hte time i could even swim that far

to me its a bit of a hobby, stops me getting fatter and stops me playing PC / xbox all day and night, you might have higher ambtions and that why i think progress is personal