Can you only speak one practical Russian? I bought that, too. I didn't read much, but they were all situational sentences that could be used in daily life, and the grammar didn't explain much. Russian grammar is difficult to understand just by looking at estimation, because it involves the change of word form.
It depends on what you have done in learning Russian. The foundation of learning college Russian is good, but there are many grammars that Russians don't use now, and Russian has no strong regularity. If you teach yourself college Russian, you will soon be confused. This book was published many years ago, and its content is very old. If you want to communicate with Russians, I still recommend All Russia, which also talks about grammar, which is quite interesting.
Make your own decisions, no matter which book is the most important, you must work hard by yourself ~ ~
It is best to buy a practical Russian grammar and oral book for studying abroad. I have studied Russian for two years and will go to St. Petersburg soon. Personally, I think it's much more practical to travel to Russia than to learn Russian at university. There are few regular Russian books, even fewer grammar books and few choices.