I'm mostly a slot player, which makes taking bonuses a little less complicated in most cases. I usually like to play a while, I'm unlikely to withdraw right away if I hit something good anyway.
3Dice's bonuses (except the SUB) are a reward for loyalty, and quite good at my VIP level. You don't get offered many in a month. Gold VIP level match bonuses don't have a WR, that is free cash for depositing. I always take mine, whatever level I'm at.
I take a lot of bonuses at 32Red. If I don't take a bonus, its because I used it already, or there is not one that day. I often bust out before completing WR, and sometimes I bust out even after a decent hit trying to finish WR. But I like the chance to play at a little higher stake, or for a little longer. I sometimes end up winning more than I would have because I do have to keep spinning rather than just cash out. 32Red and many microgaming casinos you can follow your own bonus progress easily.
RTG bonuses come in two flavours... cashable and non-cashable. I don't personally have a great track record at RTG, and I do often use bonuses to get additional playtime. Quite good hits can seem to disappear in a way I don't find at MG. And when you have to give back the bonus amount on cashing out, that definitely influences how much benefit the player receives from the bonus.
I only play two NetEnts regularly, Nordicbet and Redbet... neither offers a lot of bonuses, and most are lower percentages and on smaller amounts. They do have some low variance slots, I can usually complete a WR even if I don't have as much as my deposit left. That happens when I deposit without a bonus too, I don't have as much as my deposit left.
If you like to play more than just slots, or play really agressively when ahead, play without a bonus might be preferrable.
And to my mind, any kind of free bonus or cashback is good, even with restrictions. A second chance so to speak.